Somehow 18

28-year-old Kyung Hwi, a hospital resident, was once bullied in high school and nearly took his own life. He was saved by Han Na Bi, a mysterious girl who later committed suicide. Ten years later, Kyung Hwi wakes up in his 18-year-old body, one week before Na Bi's death. Determined to uncover the truth behind her suicide, he relives his past with the knowledge of his future, hoping to save her. Can he rewrite his story and change his fate? (Source: MyDramaList)