Keiko Ketsueki/Synopsis

History
Keiko had a relatively pleasant early childhood. Her parents were wealthy, they loved her and often praised her for everything, and showered her with attention. She in turn loved doing things that got attention, and was a loud and cheerful child. They had big plans for her life, wanting their child to be a pro hero, thinking that their quirks combined would be beneficial for heroics, dreaming about the fame and fortune she would bring to the family. Keiko herself at the time wasn't particularly interested in heroics, but if it made her parents happy she would gladly step up. However, as the years passed and she was still yet to display any signs of a quirk despite what countless doctors said, her parents grew cold and distant, bitterly disappointed that Keiko would not be able to live up to their expectations. School wasn't any better for her, as teachers turned a blind eye to how Keiko was always bullied or ignored on the grounds of being quirkless, often being called a waste of space. Her poor treatment left her with virtually no friends. As such, she became extremely withdrawn, learning early on that any attempt to garner attention would only lead to being hurt as she had no quirk with to fight back, and no one to help her afterwards as the bullies faced no repercussions and her parents didn't care at all.

Years of bullying and depression all culminated to a momentary lapse of judgement one day on her second year of high school, where she retaliated against bullies beating her up by biting them, causing her to consume some blood. With a surge of strength, she was able to escape her tormentors using her newfound quirk, Vampire Bat. Now with the knowledge that she did have a quirk after all, she was ecstatic, but when she broke the news to her parents they were extremely reluctant to believe her. They discussed on the grounds of what implications a quirk like that would have, assuming she'd have to actually cause injury or death to have a strong enough boost for heroics. Despite such a negative reaction, Keiko still loved the fact that after years of nothing they were finally really seeing and paying attention to her again, but didn't get quite the same reaction with her peers. Although her parents were reluctant to believe her, they still did in the end - whilst everyone else called her a liar and "pathetically desperate" to be relevant as to come up with such a villainous quirk. The bullying got worse for Keiko, but she still held onto the moment that her parents actually payed attention for once, and was determined to prove herself and her quirk.

The product of her desperation resulted in a violent epiphany. Keiko killed a man in the dead of night and drained him of his blood, causing the full effects of her quirk to be shown as she transformed into a human bat-like creature. Keiko initially believed that this is what would finally let her parents love her again, and proof that she wasn't useless. However, when she shakily flew back home, her parents were absolutely horrified to see their daughter as a bat creature with blood dripping from her mouth. Keiko had opened the door in high spirits, for her parents finally stopped ignoring her, and she finally had a powerful quirk - but her dreams were shattered as her parents screamed and called her a monster, which caused her to finally snap.

Seeing Keiko get angrier and angrier over her parents' outbursts, they attempt to back down, but this only angers Keiko instead. In a bloody scuffle and in a blind rage, she kills her parents. For a split second, Keiko is overwhelmed by grief and guilt, her mind racing between self-defense, years of resentment, andfinally getting revenge. Knowing her parents finally looked at her with something other than apathy and disappointment, Keiko drains both her parents of blood and goes on a murderous crime spree, leaving half drained bodies in her path.

This wouldn't last for long, as the law caught up to her and she managed to barely escape with her life by landing in a hidden alleyway. Coincidentally, Nocturne stumbles into her, and Keiko antagonises him into another fight after attempting to drain him of more blood. Nocturne subdues Keiko, who broke down crying after months on the run, thinking this is finally the end for her. Nocturne instead offers a place to stay and some food, which blows Keiko away as the first true act of kindness after years of maltreatment. Nocturne in this way becomes the first person Keiko truly trusts.