Introducing the characters:

Lee Jeno (20)

He's everyone's secret crush. Jeno is charming, quiet, and smart. The boy is the captain of the school's soccer team.

Na Jemin (20)

Na Jaemin is the school's playboy. At least that's how he usually acts. He's one of the popular guys at school who doesn't care much about his studies. 

Jung Miran (20)

She's a transfer student from Canada. Miran is smart, has a bubbly personality, and fearless. But can be too oblivious sometimes.