Seutaga Doegosipeo?

Two individuals meet unexpectedly in a theater bathroom, where a minor misunderstanding escalates when Sang-Woo misidentifies the youthful Sun-Woo as male. They ride the same train home, and Sun-Woo, a high school idol, suggests a specific arrangement to avoid attention from other women. Sang-Woo, intrigued by this girl who appears like a boy, agrees to the proposal.