Sin-goo, a 40-year-old man who owns a shop, hires 20-year old Joon-seung to help him, and the two men end up sleeping together after a night of heavy drinking. As the two men grow closer to each other, they discover that Joon-seung is the son of Seong-ja whom Sin-goo is also dating. Attracted to both the mother and the son, what will Sin-goo’s happy ending be?