HeartBeat - Season 1 Episode 3 Ah.. I told you not to open it until 100 years.
Overview: Inhae finds out that Woohyeol is a real vampire. However, what Woohyeol buys with her credit cards even makes her more shocked. She threatens to sell the mansion if Woohyeol can't repay his debt and starts living with him under a contract. Woohyeol reunites with two vampires named Lee Sanghae and Park Dongseop in the second-hand market. They lament the world in which vampires are drained by humans.