Fuyumi Todoroki/Synopsis

History
Fuyumi Todoroki was born as the second child and only daughter of Enji and Rei Todoroki from their Quirk Marriage. Enji wanted to have a child who was born with a combination of both his Quirk and Rei's Quirk. However, Fuyumi only inherited her mother's ice Quirk. Despite this, Enji seemed satisfied with his life, due to her older brother, Toya having inherited a more powerful fire Quirk than his own, and continued to train him.

The situation changed when he discovered that Toya's body was incompatible with his Quirk and Enji stopped training him in concern for his wellbeing. This affected her brother a lot, and one day he talked with Fuyumi and told her that he can handle any burns that he suffers, claiming that he knows his own body better than anyone. She tells Toya that she doesn't like to see him get hurt, but Toya yelled that she doesn't understand him because she is a girl. Upset, Fuyumi says that she is worried about him but he walks off.

Enji decided to have more children with Rei, partly to have one born with the Quirk combination he wanted, and partly to make Toya to give up. The third son was Natsuo, who, like his sister, was only born with Rei's Quirk. Several years later, Shoto was born, inheriting the Quirks of both his parents. Affected by the fact that his father barely paid attention to him due to his condition and driven by envy towards his youngest brother, Toya attempted to attack an infant Shoto.

He was stopped before he could harm anyone, but following this incident, Enji forbade all of his children from approaching Shoto so he could focus on training him to be his successor. As a result, Enji distanced himself from his other children and entrusted others to raise them, such as Rei and hired carers.

Years passed and Fuyumi developed a good relationship with her brother Toya and Natsuo, with whom she used to play. Though Enji prevented Shoto from even looking at them and forced him into brutal training. Rei had to spend time away from her older children in order to protect Shoto, but got physically abused as well. Thinking both parents were favouring Shoto, Toya's obsession to prove himself became further fuelled.

One night, Fuyumi had to hide, crying, as she overheard Enji terrorizing Rei, blaming her for not stopping Toya's secret training which caused his Quirk to keep burning him. Crying and screaming, Shoto tried to defend his mother, telling Enji not to bully her, but Enji told him to stay out of it. As a protective sister, she covered Natsuo's ears to block out the screaming. This wouldn't be the last time the older siblings heard Rei and Shoto's cries.

With Enji's increasing abuse and neglect, the family was falling apart at the seams. When Fuyumi became twelve, two tragic events happened back to back. Rei was losing her mental stability and became fearful of her own children, who reminded her of her abusive husband. Until one day, she had a breakdown upon seeing Shoto's fire side and panickily poured boiling water on him. Her mother was submitted to a mental hospital.

With Rei gone, Fuyumi and her older brothers were cared for by their housekeeper, though sometimes, the siblings needed to cook for themselves, taking it in turns. Excited after seeing his Quirk grow stronger (something that subsequently made his burns worse), Toya invited his father to Sekoto Peak to see his Quirk improvement. When Enji refused to come, Toya emotionally lost control of his flames, seemingly dying in the forest fire.

While Natsuo blamed their father, Fuyumi grieved it as a tragic accident. Rei's mental state worsened from her son's death, lengthening her stay at the hospital. With their elder brother dead and their mother hospitalized, Fuyumi and Natsuo only had each other. Despite the two incidents, Enji's obsession with training Shoto remained, ignoring Fuyumi for the remainder of her childhood.

Fuyumi knew her family was broken, but felt helpless to stop any of it. She vaguely hoped things would improve with time, so she put on a brave face at home and in public. Fuyumi became fixated that her family could become "normal" and became a hard-worker to make it happen. While Shoto and Natsuo couldn't stand their father, Fuyumi tried to get along with him, hoping it could help him to improve.

Fuyumi stepped up as the motherly figure in Rei's place, taking charge of household chores, such as cooking and cleaning. When she grew up, Enji finally allowed Fuyumi to have a casual relationship with Shoto. She helped raise her teenage brother, taking care of the "mundane parental duties", since Enji considered some of those tasks beneath him. Fuyumi would attend Shoto's school parent meetings and ensured he was looked after. This caring role extended to her other loved ones, such as delivering fresh clothes to Rei and encouraging Natsuo to go to college. Fuyumi became a teacher at an elementary school in order to compensate for the fact that she couldn't protect her younger brother Shoto.

U.A. Sports Festival Arc
The day after the end of the U.A. Sports Festival, Fuyumi is surprised that Shoto has decided to go and see their mother, wondering if it's okay if he doesn't tell their father, to which Shoto replies it is.

As Shoto leaves, Fuyumi asks her younger brother why he has decided to see their mother now after so long, but Shoto doesn't give her an answer, only that he will come back later.

Hideout Raid Arc
As a result of All Might's retirement due his battle in Kamino, Endeavor officially becomes Japan's new number 1 hero. However, Endeavor is enraged because he has become the top-ranked hero on a technicality rather than his own achievements, so when he returns home, he locks himself in the training room, where he causes great damage due to his frustration.

Later, when Shoto arrives, Fuyumi greets him tells him that she was worried about him because he didn't return her messages since he left to their mother once more. Shoto apologizes to her but their conversation is interrupted by a loud bang sounding from the training room. Fuyumi nervously informs him that it's their father, and he has been like that since returned home.

Pro Hero Arc
Fuyumi and her brother Natsuo visit their mother at the asylum. Fuyumi gives her mother a new set of clothes as Natsuo mentions they are all sensitive to heat. When her mother remarks on Natsuo being in good spirits, Fuyumi brings up him spending time with his new girlfriend who causes him to stay away, which makes him embarrassed as he mentions to keeping in contact with them.

When Natsuo brings up their father's ascension to No.1 Hero, Fuyumi chastises him but their mother tells her to let her brother continue. After Natsuo voices his resentment of his father for his ways and how it looks like he intends to leave his past behind, Rei says that's not the case. Rei mentions about a flower she received and Fuyumi is surprised when it's revealed her father has visited her mother but not seen her personally. She listens as her mother states that Enji is dealing with internal problems and he has not left them behind.

While leaving the asylum with Natsuo, the two watch a news report of their father dealing with a villain attack. She is horrified to watch as her father was overwhelmed by a villain's attack. Fuyumi continues to watch the broadcast, as her brother wonders why Endeavor continues fighting. After Natsuo becomes frantic and states Enji should just give up, Fuyumi tells him their father is the type of person who's too stubborn to ever do so.

After an intense battle, Fuyumi soon watches as her father destroys the threat and emerges victorious, to her relief.

When Enji returns home, Fuyumi happily greets her father and congratulates him on his victory. After she notices Natsuo and Shoto tensely glaring at Enji, she tells them to at least greet him as their father states that he can hear her. She watches Natsuo yell at Enji before he storms off in disgust at his father's sudden change of heart.

She panics, frantically telling Shoto that she is happy that things are getting better and hoping they might be a family very soon. Fuyumi then watches as Shoto admits he has not forgiven Enji but calls his father a great hero and is somewhat relieved. She then asks her father where he is going as he tells her he said the wrong words to her brother.

Endeavor Agency Arc
She receives a call from her father and they discuss Shoto's work at his agency. Fuyumi excitedly tells him to bring them to the house, promising an amazing dinner.

When Endeavor and the kids appear, Fuyumi greets them and introduces herself to Izuku Midoriya and Katsuki Bakugo. During dinner, she is happy with the guests enjoying the food but is dismayed by the tension between her brother and father. She tries to stop Natsuo from leaving but to no avail. After dinner, she helps Shoto and his friends clear up the table, while voicing her feelings to Shoto about things with their father. She later listens to Izuku stating Shoto is waiting for the right to forgive Endeavor.

As the boys are preparing to leave, all of them thank Fuyumi for the meal, as Endeavor thanks Fuyumi for her suggestion, to which she smiles at her father. Fuyumi then thanks Izuku for being Shoto's friend. Shortly after leaving, Endeavor and his trainees find that a villain named Ending had captured Natsuo. Fortunately Shoto, Izuku and Katsuki managed to defeat him and rescue Natsuo.

When Endeavor and Natsuo return home, Fuyumi is frantic after she heard her brother was captured by a villain. She tends to him and he states that he was saved by Shoto and his friends. She soon listens as Endeavor speaks up to commend her about the home she is trying to build for her mother to return to and voices how all he could do was rely on her.

Endeavor then declares that he will have a new house built in a more convenient location for her and Natsuo where she can welcome their mother back to. Taken aback, Fuyumi questions him on what he'll do and Endeavor reveals he intends to stay at the abode and live alone, as he realizes that the only thing he can do to help his family to take himself out of the equation.

Paranormal Liberation War Arc
The day the battle against the Paranormal Liberation Front takes place, Fuyumi informs her brother Natsuo that their father contacted her to say he won't be able to talk for a while due to work. Natsuo replies that he hopes the things don't turn out like the Endeavor's battle in Fukuoka. After this, each sibling goes to their respective places.

Fuyumi arrives at the school where she teaches, not knowing anything about what was happening in Jaku City. Hours later, she is conducting a lesson at her school, when suddenly the school staff enters the classroom in regard of Dabi's message being broadcasted all over the internet, much to her confusion. She soon sees Dabi's broadcast and is shocked to learn that her older brother Toya was still alive and had become a villain.

After the epic battle had come to a conclusion, Fuyumi, along with her bother Natsuo and her mother Rei, go to Central Hospital to visit her wounded little brother at the hospital. Shortly before entering, dozens of journalists approach them to ask about the latest events related to Endeavor and Dabi, but they ignore them and continue on their way. A doctor informs them of Shoto's condition before going into his room. They enter to see Shoto recovering and being comforted by several of his classmates, where they introduce themselves and inform them of Shoto being unable to speak due to his burns.

Shoto is surprised to see Rei among them, after a bit of talking amongst themselves, the four decide to visit Enji. They walk into his room to see him crying, and he starts apologizing profusely, saying that his regrets and guilt are too late to matter, but before he can say something about his heart, Rei comes in asking about it herself. She also tells Enji that she and her children have been bearing those feelings of guilt and regret much more than he has. Fuyumi watches as her mother tells a surprised Enji that she wants to talk about their family, and about Toya.

Following the family's reminiscences on Toya, Fuyumi acknowledges their problems and admits her own reluctance to intervene after noting it's why she tries to keep up appearances. She soon watches as her mother and Shoto motivate Endeavor in stopping Toya. Shortly afterwards, Hawks and Best Jeanist arrive to speak to them about Dabi, since they had very little info on him, deciding to help Endeavor stop him. They then ask him for information about "One For All", which Fuyumi recalls overhearing the protesters mention outside as they were entering.

U.A. Traitor Arc
In the aftermath of the Paranormal Liberation War, All For One has escaped from Tartarus, and proceeded to break into several more maximum security prisons, liberating the inmates. Due to the chaos inflicted by Gigantomachia and the mass breakout of prisoners, the whole country entered a state of total chaos and anarchy. In addition, many heroes resigned and called it quits because of the massive criticism of their work, and the destruction spreading unchecked.

Because of this, Fuyumi and her family were forced to move into the evacuation shelter at U.A. When her youngest brother, Shoto, is moving out of U.A. for good, she, Natsuo and their mother came to wish Shoto luck in stopping the League of Villains.

Final War Arc
With all the heroes fighting the army of villains in the all-or-nothing Final War, Fuyumi stays at the Underground Evacuation System beneath U.A., alongside Natsuo and Rei, where they see Komari Ikoma watching over the Masegaki Primary School students. The moving segment they are in suddenly stops and the lights go out, due to the influence of one of All For One's sleeper agents, causing Natsuo to protect his sister and mother, worried about what is going on.

With all of the heavy fighting going on due to the interference of the spies, the foundations of the blocks begins to collapse, so Gunhead orders the civilians, including the rest of the Todoroki Family, to quickly evacuate to the surface as the shelter continues to crumble apart around them. They all make their way outside, with U.A. robots there to let the civilians evacuate to wherever they want to go. However, just outside, they all bare witness to the immense heat and imminent destruction caused by Dabi's Blueflames, who unbeknownst to them, is on the verge of exploding and taking out everyone around him.

Fuyumi and Natsuo are shocked when they see their mother break away from them, and after she tells Natsuo to take care of his sister, commands the robot to take her into the center of the storm, where Endeavor and Dabi and currently fighting. The children follow their mother into the battlefield, where they see her using her Frost Quirk to attempt to shield herself from the intense heat, while also trying to cool Dabi down. They follow shortly behind her, using their Quirks to reach the rest of their family.

After Rei apologizes to Dabi, he recognizes Fuyumi and Natsuo, causing Rei to turn around and realize they followed her. She yells at them not to come, but Fuyumi tearfully replies she can't take anymore loss. She cries out to Toya not to take everyone down with him, not baring to lose anyone else. Natsuo follows by yelling at his older brother to stop causing trouble, as the three continue to blast their ice toward Dabi to cool him down. Despite their attempts, they are unable to prevent the imminent explosion as the inferno sphere starts to expand further and further around them.

Just then, Shoto enters the vicinity to the rest of his family's surprise, having blasted all the way over to Gunga from Kamino to help. He surpasses his limits and unleashes his Phosphor-powered Great Glacial Aegir, completely consuming the inferno in his ice, preventing Dabi's self-destruction and causing the fire to dissipate and burn out.

Fuyumi, Natuso, and Rei try to recover from their heat and frost burns, while Shoto stands over the crisped and partially frozen Dabi. Shoto admits that it is good they were there to help cool him down because his Great Glacial Aegir might not have been enough to stop it, since Dabi's Blueflames have been increasingly getting hotter, far beyond his reach and figuring he was not the "masterpiece creation" after all, which Fuyumi reacts to in concern.

Dabi's body begins to freeze from the inside out, and he can only croakily vent out to everyone, including himself, to just die. As Dabi lays there, a severely wounded Endeavor crawls toward his son and holds onto him, remorsefully apologizing to Dabi for not going to Sekoto Peak. Dabi responds that he hates him and his family, and Endeavor continues to break down, saying to let him have it, and starts to repent for his sins by apologizing to Fuyumi for leaving her to pick up the pieces of their family, as well as everything else he did to Rei, Natsuo, and Shoto.

Shoto eventually collapses due to over exhausting himself, while Fuyumi and Natsuo sense the threat of the Twice Double swarm rapidly approaching.