you and rin are classmates, and one bench,rin is a cold guy and always angry

the teacher gives math assignments to all students in your class, everyone in your class can, but you don't, everyone has left the class and gone to the canteen, but you are still counting,rin sees you who are in trouble, rin knows you haven't eaten

"The result is 30, let's go to the cafeteria together" rin takes the pen in your hand, then writes the result in your book