A member of Coast Guard Platoon 23, Private Kang monitors a high-infiltration stretch of beach lined with barbed-wire fencing. Driven by the belief that killing a spy is the highest honor, he waits for a chance to prove his worth.

Jeong-hye, a woman in her 30s, works at the post office and lives a quite monotonous life alone in an apartment with her cat. Apart from having lunch with the girls at work, she is all by herself, until an aspiring writer is attracted by her.

Cho Eun-ja is the president of Club LaLa, which has been a family business for three generations. It used to be a very popular club but not anymore. Now the club is in heavy debt to Eun-ja. To bring back the old days of glory, Eun-ja tries desperately to keep the club afloat while the owner of Club Nemo wants to take over LaLa. Club Nemo is also a family business and the KIMs have been rivals with the Chos. KIM wants to put an end to their rivalry by buying LaLa and building a department store. So he sets traps to force Eun-ja to sell the club. He first makes Eun-ja take out a private loan and, he snatches the only popular singer and last hope of LaLa. LaLa is thrown in a state of turmoil as it ends up on the verge of bankruptcy. As the last resort to save the club, the four girls decide to stand on the stage themselves as a dancing group named "Oh! LaLa Sisters". Thanks to their fabulous performances, they finally become popular.