It was just a sudden impulse to break away from the past… It gradually ruins men’s lives. It’s been 10 years for the 4 men to have a reunion since their high school graduation. They follow a sudden impulse to get their small revenge on a hateful teacher who had often punished them physically. It was supposed to be just a prank, however, the teacher is found dead the following day… Did anyone of them murder him? All of them deny any wrong doing. They gradually doubt gnaws at each other. This eventually makes them find out shocking secrets from their high school days. And the murder case gets another victim…