When an unknown toxic gas strikes Seoul in an unprecedented act of terror, Yong-nam has just met Eui-ju from college by chance at his mother's birthday banquet. The city falls under sudden noxious gas attack and together, they must escape the panic-stricken city.

Joon-soo is a rebellious high school kid who often get in fights. One day, his parents give him an ultimatum and leaving him alone in the house, Joon-soo decides to have a party at his parent's home. He then goes shopping for groceries and comes upon an unexpected surprise. A little toddler sits in a shopping basket wearing the name tag "Han Woo-ram" and points to Joon-soo as his father.

High school student Ha-Na experiences trouble sleeping after her classmate Jin-A committed suicide. Not being able to sleep, Ha-Na sees her parents fighting. The next day, her parents act like nothing happened the night before. She doesn't like her parents hypocritical behavior. Around this time, Se-Mi, a senior in the band club, approaches Ha-Na. Ha-Na begins to act differently, but she becomes to regret her behavior. A rumor spreads about her and she becomes the target of bullies.

A gifted swimmer rediscovers his talent by entering a competition against his long-time rival.