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 where she died in her past life, which upsets Bo Gyeom.