Gwang-sik is a single father with a son and Hae-ra is a widow with a daughter. They get remarried and become one family. Gwang-sik's son Myeong-ho and Hae-ra's daughter Dal-rae are brother and sister but they end up having sex. Their parents notice something is wrong but they pretend they don't know anything. That's because Gwang-sik feels attracted to Dal-rae and Hae-ra feels attracted to Myeong-ho. They go on a family trip to Kangwondo. They end up colliding with their sexual desires for each other and in the end, their family is reconstructed.