You and Kei are bestfriends since first grade. You're an average student and not so popular, whereas Kei is super intelligent and is very popular among girls for his looks and among guys for his intelligence. But his eyes are only on you. His strength is maths, and maths is your weakness.

Today, in maths class everything is going up from your head. You softly whispered to yourself "huh?" And Kei heard it. He briefly explained what the teacher is saying, promising to explain it in detail later.