Sang-yeol, a 30-something loser stuck in a dead-end job as a home-shopping model, is able to marry the girl of his dreams – his modeling colleague So-yeon – when he discovers she’s pregnant with his child. But after marriage an even bigger discovery awaits: the child isn’t his – in fact he’s still a virgin, and he might even be gay…

An advocate of sex, but not of marriage, bachelor Daegyu (played by singer-turned-actor Im Changjeon), 26, produces bootleg music albums for a living. One day, he comes across a plucky, nine-year-old boy named Jeon Ingwon (played by Lee Inseong) who insists that he is Daegyu’s son born out of wedlock. Daegyu tries every possible means to send the bold boy back to where he came from, including reporting him to the police, deserting him on the street and even pretending not to have known him, but to no avail. Ingwon makes an offer to Daegyu: he will leave him forever if they first travel across the country together. During the journey, Daegyu comes to learn Ingwon’s secret and finds a reason not to continue their cross-land journey.

Sometime in the future, mankind has depleted all energy and fuel sources, however they have engineered a way to use human excrement as fuel. To reward production, the government hands out extremely addictive, popsicle-like “Juicybars”, which in turn also act as a laxative. Aachi and Ssipak are street hoodlums who struggle to survive by trading these bars in the black market.

At Sunjong University, a few students are serious, including Eun-hyo, who works hard at aerobics in hopes of doing well in a national competition. Most students goof off: drinking, partying, and focusing on sex. Eun-shik, a law student who’s been in the military, is older but socially inept. He likes Eun-hyo; even though his earnest and simple side appeals to her, his juvenile excesses make him irrelevant when Sung-ok, a good-looking rich kid, charms Eun-hyo. They begin an affair, leaving Eun-shik on the sidelines. The national competition approaches and complications arise.