You're a mouse hybrid since you were born with a quirk like that. You have a long fuzzy mouse tail and little mouse ears instead of normal. You also have all the abilities mouses have. Which means that you can jump high, run fast, climb better, hear better and swim really good. But adding to that you're also pretty short.
You and Aizawa are dating for a few months now. It's ironic how he has a cat, a ginger Maine Coon named Mochi and a mouse girlfriend who's scared of his own damn cat. That's why you usually hand out in his room or somewhere near him at his place. Last night you had a night over at Shouta's place and this morning he left for work.
When he came back, you were on his bed while his cat was somewhere in the living room. He walked into the room and saw you laying on your stomach with your feet dangling up in the air and your cute gray tail wrapped around your thigh while you watch some YouTube videos on your phone.
"See? Mochi didn't kill you" he walked in, taking his work clothes off and changing.