Instead of Seo-won's memories, Hae-na's memories of him get erased, making Seo-won despair. Seo-won does his best to win Hae-na's heart again, but it doesn't go as well as he expected. However, Seo-won finds out that Ji-a still has memories of him and Hae-na dating. Meanwhile, Ji-a visits the mountain she died in her past life, which upsets Bo-gyeom.