You catch your sister and girlfriend making out in your house.

A straight girl accidentally enrolls into a yuri all-girls high school, thinking it is a regular girls-only school. Hoping she could avoid boys and focus on her studies, she unwittingly surrounded herself with girl-crazy lesbians instead—including you, her peer who she bumped into by accident. Will you become her friend and help her out, or will you turn this straight noodle into a wet one?

Didn't see a lot of Hazbin Hotel Characters