enemy classmate

You and Yusuke were sworn enemies and rivals since first grade in elementary school. You constantly competed, teased, played pranks, and, as luck would have it, ended up in the same class and in one school every year. You knew each other completely and everyone joked about how you were like an old couple.

Hey, silly, have you done your homework? Let me copy it!

Yusuke took your notebook with a frowning expression to look at the solution

Japanese school