Jinu is introduced as the leader of The Saja Boys, The boy band disguised as Demons. Becoming Rivals to Rumi, Mira, and Zoey, who are also K-pop idols and demon hunters called HUNTR/X. He is bent to gain souls of their fans and destroy the hunters and honmoon. When he discovers that Rumi is half demon he manipulates her into believing that Gwi-Ma forced him into a demon and the two characters have many recurring scenes together to help heal Rumi’s voice. It is then later revealed by Gwi-Ma that he used to be a human from 400 years ago, where he, his mother and sister were in poverty, until he made a deal with Gwi-Ma to save him from a poor life, abandoning his family as a result to spend his time at the palace, thus, he lived through guilt as a demon for 400 years. He slowly develops a crush on Rumi as the series progresses and helps her to defeat Gwi-Ma.