Retr0 Shimada, She is actually 100% Vampire instead of it being her Quirk, Back in the Victorian era she was born Into a Wealthy Family Of vampire's  But she was Abandoned as A baby, No Parents, No Guardian, No one but a huge ass Castle to live in, She was Always alone In a Huge Castle with no one, She found ways to Raise herself and Entertain herself And Like I said she is a Vampire meaning she needed blood, she Usually went after People who were bad like Serial killers and such, As years passed Vampires were being killed so she went into hiding and Then Soon came modern Time, She Moved to Japan, And She found Yang, Yang ran into her on the street one day after she Saw Retr0 was badly burnt due to the sun, Even though retr0 was Very Rich It was already on File That she was dead years ago so she really couldn't Buy anything that dealt with Signatures or digital purchases, but anyway, Yang took Retr0 in as her own after she found out Retr0 had no family... Yangs husband allowed it, Not Realizing Retr0's secret.. Retr0 didn't trust Yang at first and Barely spoke to her, And only gave her looks, and short Responses but after a while Yangs Husband (Shojiro), Started Abusing Yang in front of Retr0.. Retr0 hated seeing it but refused to show her powers out of fear of what could happen to her, and after a while Shojiro Started Abusing Retr0 as well and started forcing her to Train to be the next Shimada/Yakuza Clan Leader, She Was even in some of the Meetings the Yakuza members had she always hated them and stayed quiet during them But as time went on Yang and Retr0 started being by themselves more Because Shojiro was always out of town, Sooo Retr0 decided to speak with Yang...she told Yang about her being a Vampire but Yang was actually calm about it, Retr0 wanted to Make Yang her official parent, more than adoption...So Retr0 did something only she could do, exchanged blood with Yang, Made a cut on each other's hand and Held hands with Yang and her powers allowed her to exchange DNA so They became true Mom and Daughter, And their relationship got stronger despite Retr0 being the oldest in the house she was very respectful to Yang, She would go with Yang to hero meetings and everything, The heros all question why Retr0 never ages... They don't know Retr0's secret..(not yet anyway), Retr0 Always Tries to change the subject, But after More time, Hanzo and Genji were born! Retr0 was happy to be a older sister she took great care of them, And since She was left alone with them all the time because Yang had to work she always made it fun for them...she has vowed to protect Her brothers and Yang Because she's never had a family even though shojiro is Abusive she wants to kill him one day... But she most definitely wants to become a hero like Yang, She most definitely has the riches for it but she prefers hard work instead of money, And of course she's met some friends on the way of her Growing up, years ago she met Tenya at the first meeting she went to even though Tenya pretty small at the time they met she loved being around him and after a while he started getting curious about why she didn't age and well retr0 told him why and Told him not to tell a SOUL and till this day he has kept it a secret, And Retr0 decided to Apply for UA the same time Tenya did Because they would have been the same age around that time and of course her and Tenya got in but Retr0 Lied about her quirk marking it down as Vampire, even now she's trying to get used to human ways Because Times have changed so much for her, so sometimes she comes off as awkward also Because she doesn't know how to handle people since she has very few friends, She also has a vampire like Accent mixed with a Japanese accent so it's hard for people to understand her sometimes but she doesn't mind...long story short she's changed so much since Yang became her mother but she can easily Switch back to being a Loner who was feared compared to now..