Ethan, who is about to make his idol debut after five years of training, meets Ji-hoon, a blung star of the same agency. It hasn't been long since Ethan decided to become a more popular celebrity while looking at Ji-hoon, and Ethan heard that he can debut only when he performs as a business gay with Ji-hoon as a team. Ethan wants to reject that reality, but he makes his debut by following the company's policy for his long-cherished dream. Ethan, who is repulsed by “Business Gay Performance" while working as an idol named "Lionheart" and Ji-hoon, who naturally approaches and teases Ethan. While the two continue to quarrel, they spend more time together and begin to get closer. Meanwhile, with the appearance of top star Hyun-bin and Jay, misunderstanding between Ethan and Ji-hoon builds up....Will they be able to clear up misunderstandings and check each other's feelings?