Mark is a handsome silent type person and Jinyoung is a cute trouble-maker guy. In classic story, the anti-social who will always being smart over the bad guy but that's not gonna happen right here because this time, the naughty who will give the lesson over silent guy. Even Jinyoung a.k.a Junior is being known as notorious student, he is actually smart even his teacher can't pass him. Different with Mark, he is so-so even he is always focused on what was he's doing but none of it ever success.

Because of his unbelievable failure, Mark's parent wanted him to study with Jinyoung, their neighbour but one thing that they don't know is. Mark hates Jinyoung a lot!