She is a girl who has a cold appearance and a kind heart but is a bit of a bitch in front of familiar people. By chance, she came to South Korea to become an assistant to a group of teenagers. They are S∮M Company's test products, and they are also a group of teenagers who have gone through ups and downs, working hard for their careers until they reach the top of the "Korean Wave Emperor". There are joys and sorrows along the way, but what remains unchanged is our friendship.