"I promise you that everything's just fine! You saw my last report card, it was great, so why worry about me?"
Yumi is a model student. Not as gifted as Jeremy or Aelita, but she remains just as studious and applied to her work. She studies for her exams, unlike some of her friends; her marks are somewhat important to her (episode 42 “A Fine Mess”).
Yumi is a student who is generally appreciated by her teachers and noted for her good qualities. Even the principal thinks highly of her (episode 9 “Satellite”), which gives her the benefit of the doubt when she needs to skip class because of XANA.
Unfortunately her repeated absences and tardiness end up testing his patience and the principal now has Yumi under close watch! He threatens her with expulsion if she ever breaks the rules again (episode 64 “Double Trouble”).
Yumi is lucky, however, when she manages to get a good mark despite her secret life; not everyone is this fortunate.
It should be noted that, being older, she is in year 9 at the start of the series (a year above the rest of the group). This explains why she's sometimes away from the group, or why Jeremy sometimes has trouble warning her about XANA's attacks.
Now, she's already in high school, in year 10!
"Your telekinesis thing is really cool!"
One of Yumi's virtual character's main abilities is her exceptional gymnastic skills! Though this may seem trivial, it really isn't.
The list containing all this skill can do is indeed long! It's obvious that during the course of the episodes, Yumi often executes "handsprings". They allow her to either dodge laser fire from certain monsters, distance herself from them or even pull herself together after a fall, or an impact (episode 35 “The Chips Are Down”).
In a way, we can also say that Yumi sometimes creates a diversion as she's distancing herself and the monsters shoot at her in vain!
In certain cases, Yumi is the only one who proves to be capable of outwitting some of XANA's tricks, such as traps or obstacles in Sector 5. So, in episode 29 “Exploration", Yumi manages to reach the end of a passage full of laser beams, which her teammates would never have been able to do!
We also remark that Yumi is the best tightrope-walker of the group, with unequalled balance (supposing that balance exists in the virtual world). She can easily traverse beams in Carthage. She is therefore the ideal candidate for activating the key in Sector 5 when it's in a spot that's difficult to reach (episode 52 “The Key”).
But the virtual Japanese girl's true power is her telekinesis!
This ability allows Yumi to displace all sorts of surrounding elements, Lyoko Warriors and weapons over short or vast distances!
When she uses her gift, Yumi doesn't need to invoke it orally. She must concentrate and for that, she places her index and middle fingers on her temples. She can free one hand, either to take her weapon in case of an attack, or send more power in the direction of her target (episode 40 “Attack of the Zombies”).
As soon as the power begins to take effect, a light white aura radiates around Yumi's body. She cannot break her concentration (very much), nor attack. If this happens, the power's effect is deactivated for a brief instant, although Yumi can immediately activate it again.
The mystery of telekinesis, relative to other powers, is that using it takes its toll on Yumi. Indeed, the Lyoko Warrior often comes out feeling exhausted from what Ulrich calls, in episode 57 “Aelita”, her “telekinesis thing”. In episode 21 “Zero Gravity Zone”, Odd talks about Yumi's energy gauge... Perhaps an unknown component in Lyoko combat.
The only other example of this fatigue phenomenon is found in episode 56 “False Lead” after Aelita uses her energy field!
Despite its immense properties, telekinesis doesn't make Yumi invincible; far from it.
The major fault when Yumi is using it, aside from fatigue, is that she is forced to focus on what she is transporting. This leaves her defenceless, an open target for monsters.
On the other hand, telekinesis is a powerful weapon and an infallible shield! Yumi can lift surrounding elements in all the Sectors, such as rocks in the Mountain and Desert, in order to smash monsters or knock them into the Digital Sea (episode 63 “Triple Trouble”).
She can defend herself behind a shield made of these components as they spin around her (episode 21 “Zero Gravity Zone”). In other cases, it's possible for her to come to her allies' aid by lifting them, carrying them far away from the Digital Sea, or quite simply return a lost weapon to them (episode 56 “False Lead”).
It's therefore a dangerous power for the monsters, but also for Yumi, for whom it is exhausting.
However, after William's Xanafication he breaks the myth and slices through a rock that was coming towards him with his sword (episode 69 “Wreck Room”). Yumi doesn't lose heart however and takes revenge while fighting William in a rocky area in the Desert Replika. Craftily combining her fan-throwing skills and her telekinesis, she throws William to the ground and squashes him under a heavy, rocky column (episode 83 “Hard Luck”).
Vehicle, weapons and equipment
"Jeremy! Tell me you've reprogrammed a new vehicle!"
#32 Saint Valentine's Day
Weapon: At the time of her first virtualisation on Lyoko, Yumi had one fan to fight with. Since episode 30 “A Great Day”, she has had two, also doubling her efficiency in combat.
Her pair of weapons allows her to deal effective attacks. They move in a circular manner, which makes dodging them very hard for land-based monsters.
Yumi has not yet used her fans as a close-ranged weapon, but her throws can decimate flying creatures as well as ones on the ground. These weapons go hand-in-hand with Yumi's telekinesis.
The two weapons are always thrown with a large amount of force, allowing them to slice through several monsters before always returning to Yumi like boomerangs (“XANA Awakens”). However, monster laser fire can knock the deadly razors off course, as Tarantulas have often proved (episode 27 “New Order”).
This sheds light on Yumi's weapons' major fault: when they go out of her control, or when monsters send them flying further away from her, Yumi finds herself unarmed and must quickly recover her projectiles.
In critical situations, Yumi sometimes makes it through by combining her fan throws with her power of telekinesis, in order to correct a bad throw (episode 31 “Mister Pück”). However, when she confronts William, telekinesis is often insufficient for duping the XANA Warrior. The situation is worse still if he seizes her twin weapons, because he can then disintegrate them (episode 78 “Lab Rat”).
Also, Yumi can use her fans as defensive weapons, all while still having a lot of freedom of movement. They allow her to protect herself from laser fire, by intercepting the shots before they reach their target. Unfortunately, they aren't sufficient for deflecting Megatank lasers or William's sword; in these cases Yumi must rely on her agility.
Her fans are much more ineffective than Odd's shield, or Ulrich's sabres. Though Yumi is just as capable of parrying laser fire from Hornets or Kankrelats, she must however keep her feet firmly on the ground in order to block the powerful shots of Krabs or Bloks.
On rare occasions, Yumi can combine attack and defence in a special move: Yumi begins to spin at a dizzying speed while keeping her fans with her. This deflects any attack aimed at her back at her aggressor (episode 60 “Temporary Insanity”).
Yumi's strength comes from a combination of all her abilities. While Ulrich counts on his sabre's brute force and speed, Odd focuses on his arrows and his agility. Yumi combines all her qualities and always puts her assets to good use. She is therefore the first one to pose a serious challenge to William in episode 68 “Opening Act” and defeat him in solo combat in episode 74 “I'd Rather Not Talk About It”.
Vehicle: Yumi's vehicle is called the Overwing. It somewhat resembles the bottom half of a saucer. It's ideal for transporting a passenger, because it's a lot less dangerous than the two others. On the other hand, it can't make contact with the ground, or the rider will experience a severe fall.
It's also not as efficient as the Overboard in terms of ability to dodge, because it is larger, but its “handlebar” more effectively protects its rider from frontal attacks.
During the moments when Yumi doesn't need her weapon, she puts her fans away in the sash on her back.
Yumi is also the only one, aside from Aelita, who pilots the Skidbladnir, with guidance from Jeremy. Already having fought in the Navskids, this one again reflects the character's versatility.
"Anyway, do you mind shelving your ego for a minute? Odd and Aelita need us on Lyoko!"
Being the oldest in the group, Yumi often appears to be the most mature and rational. Consequently, the heroes listen to her and always take her opinion into account when decisions need to be made. What's more, Yumi always has an opinion to give (episode 2 “Seeing is Believing”)!
Yumi's often the one to raise her voice in order to put people in their place, calm the group down, or get something off her chest (episode 13 “Just in Time”).
On Earth, as she isn't a boarder and is sometimes isolated from the rest of the group (she isn't in the same class as them), they sometimes have to bring her up-to-date with what's going on or even come to her aid (episode 1 “Teddygozilla”)!
On the other hand, as she is serious, it's not rare for her to be the first one to touch down on Lyoko. This also often leads to her encountering more monsters than the others.
Even when she doesn't don her geisha (or ninja) clothing, Yumi proves to be a formidable fighter capable of rivalling Ulrich. She doesn't hesitate to fight XANA on Earth if need be (episode 7 “Image Problem”). Her most memorable fight is the last one she had against Xanafied William in episode 94 “Fight to the Finish”, in order to protect Jeremy. Yumi comes out badly injured, because this fight is one of the most violent in the series.
For her fans (even at Kadic Academy), Yumi is the beauty boys dream of and who is admired by girls for her behaviour and her irreproachable line of conduct and, not to mention, her courage and maturity.
"Ugh, please, Ulrich...leave me alone, I really don't feel like talking."
#15 Laughing Fit
Yumi is as mysterious as she is beautiful...
Yumi's behaviour fits perfectly with her appearance, or rather, her appearance responds to the needs of her character.
Yumi is a discrete girl who likes to keep things to herself. This temperament means that she's often distant from others! Before she joined the group as shown in “XANA Awakens”, she had no friends. We have to wonder if this reclusion was involuntary! Indeed, though she voluntarily remains close to Odd, Ulrich, Jeremy and Aelita, Yumi is less keen on being around other people. A little solitude never hurt. Thus in episode 59 “The Secret”, she reaches her limit with William's two-bit Casanova act!
Also, when something doesn't go as planned, Yumi's first reaction is to isolate herself, in her room or somewhere else. She doesn't hesitate to leave a situation if she feels she needs to.
The people who try to invade this private space Yumi needs are taking a huge risk, and not just because of Yumi's scathing remarks. Ulrich is perfectly aware of this and in episode 58 “The Pretender”, he takes advantage of it to do some hazing on Johnny out of jealousy, and sends him to go stick to Yumi like glue!
During this time, Yumi never minces her words and occasionally becomes aggressive... A legitimate defence strategy, after all... In episode 62 “Nobody in Particular”, we clearly see her take out her anger on Jeremy after he makes a grave mistake. Along the same lines, she gets upset at Ulrich when he forgets to wish her a happy birthday in episode 78 “Lab Rat”.
Selfishness, pretentiousness, injustice or hypocrisy and superficiality are just some of the things she can't stand. The Japanese teen is, by definition, the opposite of Sissi! Her morals are just and right; Yumi is a virtuous girl! In episodes 20 “The Robots” and 34 “Missing Link”, Yumi admits that Herb and Sissi have some good qualities in spite of their shortcomings.
Like any discrete person (without being a Goth, to be specific), Yumi doesn't appreciate secrets and she doesn't like talking about herself. In episode 15 “Laughing Fit”, Ulrich must move heaven and earth to get her to confide in him and say what's worrying her.
On an emotional level, though Ulrich's position is clear, hers is much more unstable; sometimes we have absolutely no idea what she's thinking.
Yumi also shows unwavering courage that never cracks in front of anyone, not even William, despite the XANA Warrior's overwhelming superiority. Her mastery of martial arts means she bows to no-one, especially boys!
Being the eldest, Yumi is also one of the most mature of the group! Not letting her emotions impede her judgement, she makes decisions she believes to be just, for better or for worse! In episode 2 “Seeing is Believing”, she makes the decision to tell everyone about the existence of the Supercomputer, because of the danger XANA's attacks present!
Speaking of XANA, even though the virus seems to make Yumi one of its preferred targets, such as in “pick on Yumi week” or in episodes 58 “The Pretender” and 61 “Sabotage”, Yumi's boldness and fighting spirit are exemplary and her determination is boundless! Out of the whole group, she's the only one to never have given up or proposed to shut the Supercomputer down.
Around her friends, Yumi is like a big sister! Trustworthy, attentive, encouraging, she's often the one who rekindles people's spirits, ignoring her own worries. During Aelita's first nights on Earth, Yumi stuck with her so that she wouldn't feel lost (episode 26 “False Start”). Out of all of them, she is the most concerned about William going to Lyoko, though she did hold it against him for getting caught. In episode 76 “The Lake”, she shows compassion while the real William is fighting against the program's grip.
Due to her maturity, she's also often the one who tells people off and dots her “i”s, as seen in episode 36 “Marabounta”. On the other hand, when Ulrich begins to take a liking to another girl, her maturity is usually replaced by jealousy and pride (episodes 22 “Routine” or 32 “Saint Valentine's Day”).
Let's add that Yumi has a sharp tongue and sometimes retaliates in order to show Odd and Ulrich their mistakes. For example, she gives Milly and Tamiya an embarrassing photo of the two accomplices in episode 92 “Cold Sweat”, as revenge.
On Lyoko, Yumi is determined but will not rush in head-first. Unlike Ulrich or Odd, she never takes pleasure in fighting and always confronts monsters with much concentration, even in the Network. XANA's strategies impress her but don't keep her down for long. A repeating habit of Yumi's is her dodging, without losing ground! On one hand, it's rare to see Yumi retreat, on the other, we often see her performing a chain of lateral dodges!
"In the race for Yumi, I'm not in first place!"
#39 A Bad Turn
Believing you're able to understand what Yumi is thinking would be total foolery! But, I am still going to try to do an analysis on the Japanese teen's cryptic thoughts when it comes to romantic feelings.
Knowing Yumi's seriousness, we highly doubt that she had any romantic history before year 9. Hypotheses remain open however, we can suppose that she did have some sort of history, however everything leads us to believe that, knowing Yumi, they wouldn't have been together more than a day...
When talking about Yumi, the word “love” remains irremediably linked to the name “Ulrich”!
The girl meets the boy for the first time at a martial arts lesson held by Jim. The two students were the only ones present and Ulrich didn't make a very good first impression! Though the Japanese girl immediately noticed the boy's charm when they found themselves on the ground together, she wasn't very convinced by his goodbye, which consisted of him holding his head high, annoyed by his defeat...
Yumi certainly doesn't fall in love within a single day, but that doesn't stop her from blushing again when she has a rematch with Ulrich. The first thing the two fighters find they have in common is their passion for combat sports and their taste for challenges.
Afterwards, Yumi was dragged into the fight against XANA, during the circumstances we already know...
Several months later, Yumi is still as discrete, but showing signs to the contrary: she's very protective towards Ulrich (episode 1 “Teddygozilla”), very jealous towards Sissi (episode 5 “Big Bug”); Yumi seems to have a thing for Ulrich!
In the cases when she passionately throws herself into Ulrich's arms and asks Jeremy if Ulrich really has feelings for Sissi, Yumi seems unwilling to provide more information! As a result, the situation becomes stagnant, with Yumi on one side not ready to make the first step, and with Ulrich on the other too shy to dare do it!
Yumi's position remains much more ambiguous than Ulrich's. Though the latter sometimes manages to confide in someone, either to Odd or Jeremy, Yumi never makes any such confession. At best, we only obtain a few implied signs...
But there came a time when Sissi wrote a false love letter to Ulrich, signing it from Yumi. Gathering up the courage, Ulrich goes to tell Yumi that he reciprocates Yumi's feelings for him (in reality, Sissi's), written in her letter.
Yumi insists that she never wrote any such letter, and instead of taking advantage of the situation to reveal her heart's intent, she lets Sissi laugh in Ulrich's face...
This creates some turmoil that won't last very long... Thankfully (episode 12 “Swarming Attack”).
Yumi's indifference ends up getting to Ulrich, who decides to start hanging out with another girl. The reaction is instantaneous and Yumi's wall of impassiveness immediately breaks to pieces, revealing a sea of jealousy. Yumi talks about it with Ulrich and he pushes her to her limits. Resisting, the Japanese girl again refuses to let her feelings known, and as a consequence Ulrich ditches her, leaving her close to tears!
On Lyoko, the attack happens in a very normal way, until Yumi is thrown towards the Digital Sea. Ulrich catches her just in time, and taking advantage of the magical moment, the two move forwards to kiss...but are interrupted too early by the Return to the Past!
Back on Earth, Yumi and Ulrich both agree to keep what almost happened a secret...
Everything was back to normal, but their states of mind had changed (episode 22 “Routine”)...
To understand the reason why Yumi would be pushed to express this secret love seems impossible. According to her, she'd rather not talk to anyone about it just yet. Is she waiting for something?
But something unexpected makes its appearance, a new desirable protagonist who's also interested in Yumi: William (episode 27 “New Order”).
Yumi very quickly realises that the young man has fallen for her... William begins a seduction game not long after his arrival; Yumi doesn't complain about this situation and doesn't dare talk to Ulrich straight away, fearing a violent reaction from the jealous boy. She hit the nail on the head, and a real rivalry begins between William and the boy, sometimes reaching worrying climaxes!
Yumi's position still remains unstable, however. Up until episode 39 “A Bad Turn”, we don't see her snub off William's “assaults”! In said episode, the boy tries to force her to kiss him. The Japanese girl pushes him away, not giving a response to William's brief question: “It's Ulrich, isn't it?”
The scene takes place with Ulrich as a witness - though Yumi doesn't know this - as he'd come to share his true feelings with Yumi... What's more, he doesn't waste time in retaliating against William; they have a fistfight.
Between Sissi, who continues to worry Yumi, and William's flirting (episode 32 “Saint Valentine's Day”), the situation takes off to a bad start, leaving not much hope of any evolution in the relationship between the two Lyoko Warriors.
We can feel their secret connection, but without this secret being revealed.
The situation doesn't really evolve until the end of the year (episode 52 “The Key”). After a new quarrel due to William, Yumi sees Ulrich arrive at her house, looking very apologetic. The boy prepares to tell her something, but he is interrupted by Jeremy.
After XANA's escape from the Supercomputer, it's time for the summer holidays and for Yumi to do some reflection!
We don't know exactly what she thought about, but when school came back, for various reasons, she brings Ulrich aside and tells him: “We can be friends, but that's all”.
Ulrich remains petrified, while Yumi answers no questions and acts very coldly; the message has been given; not understood, but definitely given.
Following these events, Yumi remains impassive towards Ulrich, not letting anyone see how she feels. The scuffles between he and William become less frequent.
For Yumi, a new problems arises!
William, unaware of the changes between Ulrich and Yumi, continues his attempts at flirting with Yumi, which she calls his “two-bit Casanova act”. William goes as far as to try and claim a kiss again (episode 59 “The Secret”). True to herself, Yumi becomes annoyed and tells him the truth! These futile incidents appear to be important, as Yumi's trust in William weakens!
Fans still await the moment when Yumi will make her choice and speak directly to Ulrich, but for now the Japanese girl's thoughts remain unknown to anyone but herself...
Despite Yumi's decision, her feelings are still there. We begin to discern them in episode 66 “William Returns”, when she wakes up after falling asleep on the boy's shoulder. The Japanese girl is still good at hiding her feelings. In the rare times when she shows them, it's when Yumi loses control of herself or is allowing several trivial things to get to her. Thus, we see her get particularly annoyed in episode 78 “Lab Rat” when Ulrich forgets to wish her a happy birthday.
In episode 92 “Cold Sweat”, Ulrich gets sucked into one of Odd's pranks and takes the blame for it himself, rather than his best friend. Odd had given the Kadic News a compromising photo of Yumi. While Yumi ruminates on her rage at Ulrich on a Replika mission in Siberia, guided by Odd, she is led to think that the boy did it to get her attention. She then goes to see him and tells him that he didn't need to do it, as she thinks of him day and night. She then gives him an affectionate kiss on the cheek.
It should be mentioned that Odd has an indirect role in the evolution of the relationship between the two. At the very least, his jabs remind us of the existence of a complicated relationship between them. Such as in episode 75 “Hot Shower”, when Odd talks about William: “Ah, the return of our tall, handsome hero! I'm sure Ulrich's gonna be thrilled to have his old rival back”!
"Then just explain to them that we're fighting in a virtual universe against a demonic artificial intelligence, that ought to reassure them!"
Yumi is a young girl of Japanese origin! Being of the nationality of the Japanese archipelago, we may presume that she was born there, but we have no information about the date when she arrived in France with her parents! What's more, she doesn't have even the slightest accent.
She is enrolled at Kadic Academy, but she isn't a boarder!
We don't know much about Yumi's childhood, only that she didn't have any friends, surely because of her introverted nature, until the day her whole life turned upside-down!
Several days before this event, Yumi spent her life at Kadic Academy as a hard-working and serious student like any other! She still pursued extracurricular activities and attended a night-time martial arts class held by Jim, the sports teacher!
There, she “met” another young man who she fought against, throwing him to the group with a superb kick! However, as the two teens grappled on the ground, Yumi couldn't help blushing due to the proximity between her face and Ulrich's.
Annoyed at his defeat, the boy left without bowing, nor saying goodbye, leaving Yumi speechless.
Her proud adversary isn't satisfied with his defeat and one day later, he and Yumi find themselves facing off yet again in the gymnasium, ready to fight! After exerting a lot of energy, the two students find themselves face-to-face, blushing and admiring that the fight ended in a draw... Yumi's rival then introduces himself: “Ulrich Stern”.
Each such situation has its disruptive element: to Yumi's utter confusion, a ball of moving energy materialises in the gymnasium and goes after them! Stupefied, the Japanese girl lets Ulrich lead her behind a door. The boy then calls his friends and prepares to leave, but Yumi will have nothing of it! She holds Ulrich back, demanding he tell her what's going on and who XANA is! Not backing down, she is soon brought to the factory through a passage in the sewers, then ends up falling in the middle of a rather diverse group of students!
Ulrich, the handsome and mysterious boy, the one and only Odd, with rather colourful clothing, and finally Jeremy, who, with his first-in-class appearance, seems to be the brains of the group!
The following events were a real crescendo! Caught up in the group's flow as they spoke in very cryptic jargon, Yumi is taken to the abandoned factory before finding herself in front of an important computer complex, with Jeremy at the controls! The genius proposes that she take a dive as well, which she doesn't understand! Yumi doesn't seem very sure of herself in the scanner before being dematerialised, and then virtualised!
She lands in a glacier-like virtual sector! What's more, she is wearing the costume of an Oriental princess, as she formerly was in her country!
Yumi had become a Lyoko Warrior, for better or for worse!
After fighting against monsters to save the life of a virtual girl, Yumi is brought back to Earth, then into the past! Now, she's part of a group of her new friends, prisoners in a grand adventure! An adventure that will last until Jeremy finds the way to materialise the virtual girl named Aelita! Also, the Japanese girl learns that their enemy, the same one that generated the energy ball and that controls the monsters on Lyoko, is called XANA, a multi-agent program that seeks to destroy the world!
A new chapter commences in the life of Yumi Ishiyama!
Months pass, the fights against XANA is restricted to deactivating towers on Lyoko, saving the world, coming back in time, etc. Yumi always performed her missions brilliantly, slaying monsters with her fans!
However, as for any other hero, life wasn't always easy, especially for Yumi, who is one of XANA's favourite targets, as we can see in a series of episodes (nicknamed Pick on Yumi Week by some fans) from number 6 “Cruel Dilemma” to 10 “The Girl of the Dreams” in which Yumi falls into the Digital Sea, is imprisoned by a Guardian, chased by an alien, tracked by a military satellite and attacked by a possessed suit of armour!
Yumi escapes death several times, always saved just in time by the Return to the Past! One day, she really does die by falling into the Digital Sea! She can only be saved by sacrificing Jeremy's materialisation program!
XANA is one thing, adolescence is another! If confronting an evil power that wants to exterminate the world wasn't enough, Yumi is faced with turmoil and problems other kids her age find: she needs to manage her relationship with Ulrich, which is constantly under threat (episode 12 “Swarming Attack”) or put to the test (episode 22 “Routine”), safeguard her family when her parents fight (episode 15 “Laughing Fit”)...
Yumi fights alongside the others to materialise Aelita, nourishing the hope that the Supercomputer can finally be shut down and she and her friends can live a normal life!
Aelita will be materialised, but due to Aelita's missing fragment, the Supercopmuter cannot be extinguished! What's worse still, XANA shows itself to be more intelligent, sharper, more powerful, more dangerous...
This said, Yumi stays true to herself, courageous and determined, confronting any Tarantula, Scyphozoa or Xanafied person without backing down!
A new person will enter her life: William! The boy reveals to fall very quickly in love with Yumi, which doesn't daunt the Japanese girl; far from it (episode 27 “New Order”)! However, as she foresaw, the arrival of this new pretender sparks an impassioned war between William and Ulrich, complicating things already soured by Sissi...
A teenager's life is so complicated!
Yumi, a serene young girl in the middle of a hailstorm!
Worries never truly stop raining on the Japanese girl!
Between XANA, who continues to create trouble, like by stealing a fragment of her to prevent rematerialisation until the Lyoko Warriors get it back (episode 35 “Missing Link”), Yumi must also face the wrath of her parents, who take notice of Yumi's nocturnal outings to the factory (episode 29 “Exploration”)! They even think about moving because of the loss of Mr Ishiyama's job (episode 35 “The Chips Are Down”).
If only that were all... To add to the bad luck, Yumi's setbacks become of increasing strength! XANA kidnaps the Japanese girl using the Xanafied principal (episode 41 “Ultimatum”) and sending a polymorphic clone to make romantic mischief in the group (episode 43 “XANA's Kiss”). After a bug occurs in the scanners, Yumi accidentally finds herself in Odd's body and almost experiences complete disintegration (episode 42 “A Fine Mess”). The war between Ulrich and William doesn't help matters, especially when the two love interests duke it out (episode 39 “A Bad Turn”).
While Jeremy's research on an antivirus progresses, XANA reaches the peak of its power and sends a clone of Franz Hopper to make its enemies believe that prolonged exposure to the scanners has caused a high risk of cellular degeneration in Yumi! The Japanese girl then gets enraged at Jeremy and the boy is isolated from the group! The group later discovers the true nature of the false Franz and Jeremy relieves Yumi by telling her that she isn't suffering from cellular degeneration.
The day of truth about Aelita's missing fragment arrives and just after a row with Ulrich, Yumi dives in with the others to get it back! She is powerless against the trap put in place by XANA and watches helplessly from the laboratory as Aelita is robbed of her memory by the tentacled monster and XANA escapes from the Supercomputer!
Aelita is brought back to life by Franz Hopper, and then the heroes promise to continue their fight against their arch enemy!
The summer holidays go off without a hitch, with XANA remaining calm on the network! Its objective to destroy Lyoko appears and Yumi gets to work defending the Core of Lyoko (episode 53 “Straight to Heart”), and preventing the destruction of the Surface Sectors (episode 59 “The Secret”).
To limit any conflict between Ulrich and William and cease the ambiguity between her brother in arms and herself, Yumi reflects during the holidays and tells Ulrich flat out: “We can be friends, but that's all”!
William no longer has the right to direct treatment, however be begins to get exasperated with the Japanese girl always changing her mind! Yumi then begins to be wary of her friend and denies him entry to the group by voting against William joining them (episode 59 “The Secret”).
This may appear repetitious, but nevertheless Yumi remains one of XANA's favourite targets! She's the focus of numerous attacks: Xanafication of her whole class (episode 54 “Lyoko Minus One”), taking control of a huge murder of crows to give her fatal injuries (episode 58 “The Pretender”), taking control of vegetation to drag her into a quiet part of the park (episode 61 “Sabotage”)...
Yumi doesn't manage to save the Mountain Sector (episode 64 “Double Trouble”) and it is annihilated.
Following some handy help from William, she finally gives in and accepts to allow him into the group, telling him the good news herself!
She quickly regrets her gesture.
Not long after, she arrives for a battle in the Core Room and realises the boy has been Xanafied, and he devirtualises her as well as the other Lyoko Warriors.
Like the others, Yumi helplessly witnesses the destruction of Lyoko.
She is evidently present with the others when a message arrives from Franz Hopper in the network...a new spark of hope.
In the quick succession of the recreation of Lyoko and Dark William's appearance, Yumi is a first-class asset to the group. She is the first one to cause difficulties for the XANA Warrior on Lyoko since episode 68 “Opening Act”. She's the first Lyoko Warrior to win a duel against the big baddie (episode 74 “I'd Rather Not Talk About It”). Her flexibility and holistic approach during clashes pay off more than Odd and Ulrich's rushing in head-first.
Furthermore, Yumi is more capable than the others of destabilising XANA's hold on William, as seen in the famous seen from episode 76. It's on this occasion that we discover that the Japanese girl could be the most affected by William's disappearance. Also, she manifests a certain benevolence for the terrestrial clone of the missing boy.
On Earth, when she isn't being attacked by an enraged clone (episode 69 “Wreck Room”), she covers Aelita by taking care of possessed people (episode 72 “Crash Course”). Apart from the two geniuses in the year below, she's the one who does best with computers. She progresses to the point of being able to set up a delayed virtualisation (episode 76 “The Lake”).
In the Network, she seems less comfortable in the Navskids than the two masculine daredevils on the team. Her discovery of the Digital Ocean derails when she is lost in the aqueous immensity (episode 77 “Lost at Sea”). Her friends save her from Kongres and William's Rorkal just in time.
When Teleported, Yumi excels even more than on Lyoko and inflicts severe blows to XANA's agents. We mention episode 83 “Hard Luck” wherein after coming back from a Teleportation, she delivers the worst clobbering to William that he has ever experienced.
The student also experiences bad days during the conflict. Struck down by Xanafied bikers (episode 80 “Dog Day Afternoon”), defeated by William during Teleportation (episode 92 “Cold Sweat”), by the Kolossus on Lyoko (episode 93 “Down to Earth”) and severely mistreated by William during the final conflict on Earth (episode 94 “Fight to the Finish”); Yumi once again bears the brunt of XANA's anger.
As she doesn't have a taste for combat, she watches relieved as her viral enemy reaches its end.
When the moment to shut down the Supercomputer comes, she is the one who pushes the most for it to be done. She holds no regrets nor remorse, and is even astonished to find out that her brothers and sister in arms are hesitant to turn the page. After a glum day, she makes a gesture and reaches out to Ulrich, reassuring him about the future of their group and the happy days they have ahead of them.
The team, reassured and more sedate, assembles in front of the machine to finally shut it down.