Daisuke's older brother, Takashi, has no permanent job and just hangs around, begging for money from Daisuke. His wicked hobby is to invite female insurance salespeople to his house and forcefully have sex with them. His next target is Mina, Daisuke's homeroom teacher and first love from his school days, who has changed jobs to become an insurance saleswoman... Daisuke accidentally witnesses his brother and Mina having sex...