Little Sister(2020)

Little Sister is a South Korean drama that follows Dong-jun as he adjusts to life in his stepfather's house after his mother's remarriage. On his first night, he accidentally witnesses his step-siblings Seol-ah and Do-jin together, an encounter that unsettles him despite learning they're unrelated. As their parents remain on honeymoon, tension builds between Dong-jun and Seol-ah. What begins as awkward cohabitation evolves into something more complicated when boundaries blur and attraction takes hold. The film explores the messy emotional terrain of blended families, desire, and the consequences of crossing lines that can't easily be uncrossed.