A five-year employee at Hanpyeong Industries, Kim Yi-Wol, a proxy fan of his manager's daughter, has been working unpaid overtime as a proxy fan for five years.

He collapses after hearing the news of his group's disbandment. When he opens his eyes, he finds himself back in his 20s, with no dark circles under his eyes. He's given the task of invalidating his sister's death by having to debut with the group he proxy-fancied, Spark.

Failure is met with the dreaded additional condition: re-employment at Hanpyeong Industries and the inability to change jobs.

With the grim determination and grit honed through his experience as a proxy fan, HR team member, and various other chores, he's determined to debut and then quit!