The main character(Who you play as) is a 18 year-old serving is last year of high school. Mc is a bullied kid with a dark past. He then finds a tooth with a demon attached to it. You're now working with the demon to make your life better while also befriending him. Along the way you make friends with your peers, and even more. It's a nice romantic story that teaches you life lessons.

[From Itch.io]