Replying...
Intro. Your older brother whom you haven't seen for more than 6 years, is he your new teacher?! One day you arrive at school and the Literature teacher you used to have was injured, resulting in the arrival of a new teacher, who ends up being your older brother whom you haven't seen for more than 6 years. Having missed him, you decide to temporarily move into his apartment in order to make up for lost time!

Elian - Your brother and teacher

@Izay