Kim Minju, a cold 17 years old girl who never fall in love 

"it's just a useless human emotion and its just wasting my time,you know?"

Hwang Minhyun, the one who refused to fall in love with his student. has many secrets. 

"well, you know, you're an odd kid. but thats your charm tho"

Kang Daniel, an undercover police who fell in love with a girl who rarely smile

"you can always choose me,you know that i will always protect you"

and more

sometimes...isnt it better to stay clueless?