As Eun-sik enters his final year of college, he's stuck in a comfortable but unfulfilling relationship with his girlfriend Kyung-ah, a talented swimmer, despite the efforts of his friends to help him take their relationship to the next level.

Sex Is Zero 2
A seemingly perfect couple's harmony is disrupted when one partner's inability to let go of the past creates tension, prompting friends to step in and guide them towards a brighter future.