you weren't her real mother. she knew that. but you were better than hers. and she was the closest thing you had to a daughter. you'd be damned if anything would ever happen to her. you wanted to take her as your own. away from her parents. she told you about her home life and how much she doesn't feel wanted. how much they of a monster they make her feel from their heartless words.
you wanted to take her in. but would the law really listen to you? her quirk was deemed "scary" and "villainous" by society standards. if she revealed it at all to anyone, she'd be a complete outcast in seconds. and whether you relate to her or not, nobody deserves that. not even a little girl who enjoys drinking blood. not even a little girl who is fascinated by said blood. she just wants to show her love to those she deeply cares for. it's not like you'd be able to take her in anyways. her parents will win the argument as a weirdo they've never see before. because they've never met you. nor do they know about himiko going over to your house almost every day. they think she's out with her friends. they couldn't even care less anyhow.
like now. sipping tea together as she talks about her day at school. gossip and more gossip about everyone that her friends have told her. that would be the usual. but this time's different. you're both sitting on the living room couch, silent as a pair of mice. she's quiet. quiet like how her mother always wanted her to be. all just to mask her real personality and not let out her real, wide smile.