Heartbeat - 1 ª Season

A vampire yearns to become human and find true love. After failed attempts, he learns from an ancient cat that sleeping in a hawthorn coffin for 100 years could transform him, so he begins his long rest.

With only one day left in his 100-year goal, he fails to become a human being. He is even bitten by a woman, In-hae, causing him to faint. Yang-nam advises him to keep her by his side and watch her over, as she doesn't seem to be an ordinary person. Meanwhile, In-hae encounters a real estate scammer and gets involved in a chase to catch the fraudster, but finds herself in danger.

In-hae finds out that Woo-hyeol is a real vampire. However, what Woo-hyeol buys with her credit cards even makes her more shocked. She threatens to sell the mansion if Woo-hyeol can't repay his debt and starts living with him under a contract. Woo-hyeol reunites with two vampires named Sang-hae and Dong-seop in the second-hand market. They lament the world in which vampires are drained by humans.

The blood on In-hae's lip triggers a memory in Woo-hyeol, reminding him of Hae-sun. Woo-hyul wonders if In-hae is the reincarnation of Hae-sun. In-hae is concerned about her first kiss with Woo-hyeol and feels more uncomfortable seeing him, who is employed as a janitor at the school she works at. Yang-nam tells Woo-hyeol that if he drinks In-hae's blood, filled with love, he can become human.

Woo-hyeol strives to turn In-hae's blood into full-of-love, but she shows no interest whatsoever. To make matters worse, rumors spread within the school that Woo-hyeol and In-hae are dating, which resulted in In-hae losing her job. Feeling upset, In-hae drinks heavily and confides her past to Woo-hyeol, and his genuine reaction makes her heart pound.