"Such a great feeling when I can call you oppa." Linzy (린지), 15 years old girl who really in love with one of the member of rookie boyband called Bangtan Sonyeondan (방탄소년단), Jeon Jeongkook (전정국). She really like madly in love with a boy not an idol maybe she is. 

Based on Tagalog's movie, "Crazy Little Thing Called Love a.k.a First Love". Not copying all the story.