A song like a miracle falls in front of 20-year-old Joseph who has nothing. One day while they were having a happy time singing 'that song' like fate, a man with everything, even the owner of the song, appears in front of Joseph.

Four high school friends maintain their ties but finds themselves in very different situations when they reach 21. Chu-won was a promising athlete but, drinking heavily and unable to get past an old flame, he ruins his prospects. Goo-rim became on idol singer, but a drug scandal has seen him fall on hard times. Seo-won, as a medical student at a top university, was faring best among them, until he is diagnosed with leukemia and falls for a teenage escort from their old high school. Meanwhile, Dae-sung is a sex addict with a penchant for mature women who dreams of making his own film.

Ga-young, a filmmaker, visits Seong-bum, an art instructor, to consult on her affair with a married man. The two were once lovers of each other, though that does not stop Seong-bum from becoming a love counselor for Ga-young. Yet, they don′t just consult, but begin exploring new feelings for each other.

Chinese secret agent Da-hee receives intel that a large number of illegal firearms are being smuggled into Korea and is sent to investigate the case. She meets Su-han, who is supposed to help her with the case, but due to his lackluster skills they fight over trivial things. But as their witnesses are suddenly murdered, the two of them quickly become the prime suspects.