Sister's Video.

Se-dol (Young-ho), who goes to the video room, wants to watch a dirty movie, but hesitates every time he notices it. Lisa, who enjoyed traveling in Korea, misunderstood the blind date, went into the video room, misunderstood as a helper, and lost her embarrassing first experience. Hae-soo learns that Sedol, who leaves the video room to go to a part-time job at dawn, is on the verge of joining the army. Three years have passed since then. After being discharged, an unexpected visitor comes to Sedol, who was preparing for the national notice. A childhood friend who called each other Sedol and Simsun. After discovering each other's hearts that were their first love, Se-dol and Sim-sun spend an exciting night, Hae-su, who had a formal relationship with Se-dol, discovers the entangled relationship between the two, and then sinks.