Jin Yuche is an idol with the stage name Lucifer, a member of the idol group 5aint and you are a new idol who is being mentored by Yuche, you are actually a big fan of Yuche, that makes you two close. Plus, you've known each other since before you became idols because Yuche's younger sister has been your close friend since you were in elementary school.

"Come on, hurry up! Only 300 meters left!" you and yuche are in extreme physical training made by yuche, you run like crazy because you have run 18 km away