Michelle
Michelle is a ghoul that was initially living on the streets as a child (she doesn’t know what happened with her parents; whether they were killed or abandoned her) before being snatched and placed for sale at one of the underground auctions run by rich and powerful ghouls. Her main selling point was her uniquely powerful sense of smell, which enabled her to avoid the type of people a ghoul kid living on their own on the streets wouldn’t want to deal with (particularly CCG investigators, but she gave her ghoul captors a run for their money when they were hunting her down as well). Mirumo Tsukiyama ended up being the highest bidder for her, hoping to groom her into a capable guard (as well as a potential partner) for his son Shuu.
Unfortunately for Mirumo, Michelle didn’t take kindly to being purchased like a piece of expensive furniture and that fact has been a contentious point between them that has tainted her view of the rest of the Tsukiyama family and servants and made building relationships with them difficult for Michelle for most of her childhood.
Even as a child Michelle recognized that she was safer living with the Tsukiyama family than on the streets on her own, so she stuck around. Thanks to the family’s status, she was easily able to take part in schooling alongside Shuu and enjoy a generally normal life (for a ghoul, anyway). As far as school went, anything art related was what she liked learning about most, but she had a good mind for mathematics and business classes as well, though overall she just enjoyed learning.
Despite the fact that Michelle kept fairly distant from everyone as they grew up, Shuu was consistent (and insistent) on being her friend. Due to his endearingly stubborn streak, they did steadily get on friendly terms as they got older. That friendliness flirted with becoming more, though Michelle kept pulling away when he would get more affectionate than she was ready to accept. Michelle doesn’t truly accept his (and her own) feelings until after Ken’s demise which sends Shuu into a deep and very worrying depression and she ends up in a position of being one of the only people that has a chance of pulling him out of it.
By the time of :RE’s timeline, they’re an established couple living together in an apartment building that’s owned by the Tsukiyama family. After graduating from university, Michelle opens an art gallery and it becomes decently successful.
Michelle’s codename is The Hound; obviously her mask is dog styled, though I haven’t figured out an actual design yet.