HeartBeat - Season 1 Episode 4 Ah.. I told you not to open it until 100 years.
Overview: The blood on Inhae's lip triggers a memory in Woohyeol, reminding him of Yoon Haeseon. Woohyeol wonders if Inhae is the reincarnation of Haeseon. Inhae is concerned about her first kiss with Woohyeol and feels more uncomfortable seeing him, who is employed as a janitor at the school she works at. Cat Man tells Woohyeol that if he drinks Inhae's blood, filled with love, he can become human.