Despite their different family backgrounds, four friends grew up together in the wearisome years of the 70s. But as time goes by, each of them takes a different life path.
The story of two brothers, the younger one of whom has a rare disease which causes his body to age rapidly while his mind is still in a pre-teen state.
Young-Hoon works for his mother’s restaurant, but he prefers hanging out with his friends. He then meets Yeun-ah, a tough lady that works in a room salon as a barmaid. She takes the initiative by coming to his restaurant, when he is working, and propositions him in a playful way. They become a couple, but their relationship is always volatile. They fight constantly (physically and verbally), but the next moment kiss and make up. Meanwhile, Young-Hoon already has another girlfriend, who is his finance!
Ji-eun has a bad impression of men due to bad experiences with her father but her mom Hyeon-ah convinces her into getting tuition from an art student. Jeong-woo is surprised at how cold she is towards him but at the same time, there's tension between the two. Meanwhile, Hyeon-ah, who is afraid something might happen between the two, calls Jeong-woo in and suggests something but he confesses his love for Hyeon-ah instead. They have fallen into an unappropriate relationship and Ji-eun decides to give her mom a surprise.
Tae-su, a detective fighting organized crime, returns to his hometown for his high school friend Wang-jae's funeral. There, he meets his old friends Pil-ho, Dong-hwan and Seok-hwan and they reminisce. Suspecting something fishy about Wang-jae's death, Tae-su and Seok-hwan start investigating it, each in his own way. Their investigations lead to a land development project that Pil-ho is directing.
Celebrity guests are split into two teams to compete in various contests. One guest, known only to himself, is designated the "X-Man", and does his best to cause his team to lose the contests. At the end, all guests try to determine the X-Man's identity.