1921: In Gyeongseong, a Japanese soldier pulls a Korean schoolgirl into an alley to chop off her braid. Han Yi Na, a vampire, intervenes to protect the girl. 2021: In Seoul, fellow vampire Lee Ji Yeon introduces Yi Na to social media.
When a young woman accuses Yi Na of using filters to enhance her profile photo, Yi Na invites the woman to the Bite Sisters dress shop. After hearing the young woman's story, Kim Mi Sook, the proprietor, gifts her a more flattering outfit.
Jung Sung Min applies to work at Bite Sisters after spotting Yi Na, who he recalls giving him food as a child. Mi Sook, a vampire, who thinks Sung Min is the reincarnation of Yi Na's lover from 100 years ago, hires him. Yi Na is surprised.
Yi Na suggests how Ji Yeon's disgruntled employee Eun Bi can get revenge on Ji Yeon for being such a demanding boss. Yi Na is disturbed that Sung Min appears to be the reincarnation of her former lover, both in appearance and behavior.
Sung Min notices that neither Mi Sook nor Yi Na appears to eat anything. He also notices that Yi Na behaves strangely after he cuts his finger and finds photographs of her over a period of many decades in which her appearance is unchanged.
Ji Yeon puts an end to the male team leader's sexual harassment of female employees while they are alone together in an elevator. Mi Sook intervenes to help a woman being harassed by a man. Sung Min reminds Yi Na of her former lover.
Eun Bi learns that the male team leader has stolen Ji Yeon's design idea. Mi Sook startles Sung Min when she tells him not to believe Yi Na if she claims to be drinking human blood, particularly since Yi Na did not make such a claim.
Ji Yeon foils the attempt of manager Choi to steal her work, winning Eun Bi's support in the process. A young girl visits the dress shop to buy a jacket for her mother. Sung Min and Yi Na offer to walk the girl home afterwards.
Sung Min witnesses Yi Na strangle a man who has been extorting money from the mother of the girl who came to the dress shop. Sung Min questions Yi Na about who she is. She refuses to explain. He decides to quit his job at the shop.
Mi Sook befriends the woman who has been leaving food for cats in the alley outside the dress shop. Yi Na asks Sung Min to return to the store. Sung Min reveals his love for her despite his suspicion that she is a vampire.
