HeartBeat - Season 1 Episode 9 Ah.. I told you not to open it until 100 years.
Overview: Doshik discovers that Woohyeol is a vampire and tests Inhae, who unexpectedly protects Woohyeol. Woohyeol, troubled by the fact that he needs Inhae's blood to survive, faces additional challenges when Haewon becomes more affectionate towards him. Desperate to obtain Inhae's blood filled with love, Woohyeol's heart is tormented.