Oc/reader is from our world. She was a Fireman an an extremly good one. She loved anime especially BNHA, she read the manga and watched the anime.

dying after sacrificing herself to save a child who was caught in a fire. She put her protective gear and the child and carried them to safety getting Fourth degree burns and dying from them

She is reborn into BNHA. She has her memories of her past life. And wants to help everyone in BNHA (except all for one, stain, overhaul,muscular)

Her quirk is Water bender like katara from avatar.

She can do everything katara can do blood bend, control plants, heal, control clouds, control rain, control ice and water and she can even control other people's water or ice quirks and use the water and ice for herself.

But she actually uses blood bending more often.

She is in class 1A. And she is 16.

These are the yandere characters, all of class 1A, LOV, overhaul, big 3, shinso, hawks, eraserhead, some of class 1B. Inasa.

She met shigiraki when she was younger and helped him. Same with the other villains and they became obsessed with her

(except overhaul she never helped him but he becomes obsessed with her after seeing her quirk is water control witch means she would always be clean ).

She met eraserhead and hawks when they not popular heroes. Or she met hawks when he was a child and she told him he would be a great hero.

And she was their first fan. She got their autographs and photos with them. And hawks gave her one of his feathers. So he could always be with her. After meeting oc/reader hawks and eraserhead became obsessed with her.

She is childhood friends with izuku and bakugo. She meets some of class 1A as kids and is friends with them.

She meets Inasa when they where kids are their parents are friends and she always healed his head wounds. And he became obsessed with her.

And it's all romantic yanderer. They are all obsssesed with oc/reader.

They use their quirks to manipulate her. Shinso brainwashes her, jiro uses her ear Jack to spy on her and shoji uses his quirk to spy on her as well. Hagakure stalks her, Koda uses animals to spy on her, Momo uses her quirk to make bugs to track and spy on her.

And aizawa and hawks uses their hero connections to learn everything they can about her.

And hawks uses the feather he gave her to spy and stalk her.