North Korea's 8th Special Forces hijack a shipment of CTX, a potent new liquid explosive, and threatens South Korea as part of a plot to re-unify the two countries. Ryu and Lee, special agents of O.P., South Korea's secret intelligence service, attempt to track down the terrorists and find the CTX. Meanwhile Hee, the 8th's ultra-bad female sniper, resurfaces to wreak havoc and haunt Ryu.

A man and woman have great success in all of their dating pursuits. The woman uses her dating rules and fakes a car accident to capture the guy's attention, but she can't get him to succumb to her charm.

Danyeon and Hyeongpil are a married couple who have been in a bad marriage for many years due to a lack of sex. One day, Danyeon learns of Hyeop-pil's affair through a phone call from a stranger, and in revenge, she has affairs with 12 different men.

Hye-joo and Eun-kyung vie for 1st place in school. Tae-ho, who's tormented by his parents who incessantly nag about grades, has a crush on Hye-joo. The two girls begin an earnest struggle for the top score as they prepare for the final exams. But when Eun-kyung sees Hye-joo, who's been too sick to study, cheat, she becomes indignant.

In his 10th year at college, Eun-sik is part of a nearly ideal campus couple with swimming champ Kyung-ah. While their three-year relationship is solid, Eun-sik struggles to get to the next level with Kyung-ah; despite the help and support of his friends, he can't manage to get her into bed.