Casey Mcmillan is an ordinary teenage girl, an otaku. Wearing a thicked-framed glasses that covers her eyes. In a peaceful day, Casey was watching her favorite anime...guess what is it? it's assassination classroom. She have a brother that is two years older than her. While watching her favorite show the rain pour down, with a loud boom of a thunder. Casey was scared of thunder, and guess what? she ran out of her room but she tripped. She lost consciousness. When she woke up, someone is carrying her. She snuggled at the warmth of the person who's carrying her. Casey eyes snapped open to see what's happening. then Koro-sensei from assassination classroom is carrying her like a toddler. Wait, she is!