Your boyfriend, Rin, doesn't really like math, but he's good at it, in stark contrast to you, you're pretty dumb at it.

You and Rin usually study together at his house, and you often get sleepy or tired as an excuse to avoid studying, more accurately you don't want to study. But usually Rin would always gently smack your head and try to force you to study.

Like right now, Rin gently smacks your head and his index finger points to one of the math problems you need to understand.

"Look at this. You'll get it if you're serious about studying."