Is it Okay for a Murderer to be an Idol?

Summary

[Witnessing a fellow idol group member's murder scene.] Lee Yu-min begins his activities withhis second group debut, determined not to fail this time and to succeed unconditionally. While practicing for an important year-end awards stage, he witnesses the scene of a murder committed by his older brother, the leader, Han Se-gye. While Se-gye threatens him to keep it a secret for the sake of the group, he also showers him with more aggressive physical affection than before . Yu-min feels a flutter in his heart and is left in great confusion... 'I must be crazy... Why is my heart racing for a murderer?!' Between the cold- hearted killer and the affectionate team leader and older brother, what is Se-gye's true nature?