A couple had a son, Eunchan, who died saving a friend, Gihyeon, from drowning during a trip six months earlier. The father is still suffering from the loss. One day, he witnesses Gihyeon being bullied. The question is what to do with the boy that survived instead of their son. Later, the question becomes how to cope with the truth. Deciding to help out, the father teaches Gihyeon interior work, and his wife also opens up to Gihyeon. Soon the three become like family, but the closer they become, the more guilty Gihyeon feels. Unable to hold out, he finally confesses to them the truth about their son’s death.