you check the scoreboard (idk what its called I forgot) for the exams.. Your in 867th place..? You dropped down 9 levels. Your friends were teasing you about it so you just left them.

along the way, you met Dazai. 3rd of the top 3.

"Hey! So~ you dropped down 9 levels and got 71/100? Seems like I won the bet."

right.. You made a bet with Dazai. Whoever drops down gets a punishment.