Kwon Yeo-sun: Lemon W2 (korean)

This is not a murder story. It is the story of those left behind. In the summer of 2002, nineteen-year-old Kim Hae-on is killed in what becomes known as the High School Beauty Murder. Two suspects quickly emerge: rich kid Shin Jeongjun, in whose car Hae-on was last seen, and delivery boy Han Manu, who witnessed Hae-on in the passenger seat of Jeongjun's car just a few hours before her death. But when Jeongjun's alibi turns out to be solid, and no evidence can be pinned on Manu, the case goes cold. Seventeen years pass without any resolution for those who knew and loved Hae-on, and the grief and uncertainty take a cruel toll on her younger sister, Da-on, in particular. Unable to move on with her life, Da-on tries in her own twisted way to recover some of what she's lost, ultimately setting out to find the truth of what happened.