S01E52 — And Then There Were No Delinquents

It's the coldest day of Winter and St.Ishiyama is closed, however everyone from Ishiyama has still come to school as they were not informed of this until Kazuya and Azusa come in to tell them. Unable to go home due to the storm, everyone remains in school, until suddenly the delinquents slowly get beaten up - Kazuya then informs the others that the incidents are exactly the same as that in the counting song "100 Delinquents". As the song's events continues, everyone decides to try and capture the culprit however all the men are eventually beat up leaving only the women remaining. Aoi then realises that the culprit is actually Koma, who wanted the women to warm each other up naked in the cold, whilst he stayed in the middle - and so beats him up.