Characters:

St. Jaeneung Academy (black-white uniforms):

Kim Ryeowook (SJ): Ryeowook is a small student with a peppy personality, which usually cause him to get in trouble. Besides that, as a new student, he dosen't know about the school's traditions, which some of his new fellow students don't really like about him. But he has a gift of energizing the people around him. From his first day on, he has a strong attraction to Kyuhyun, who would be Ryeowook's very first love.

Cho Kyuhyun (SJ): He is the current 'Wang', who is a highly respected and very beloved person to most of the students attending the three schools. He looks handsome, but still mysterious and he seems to have a quite high number of secrets, which makes it difficult to figure out his personality or even to talk to him. He likes to play the piano and most of the time, he dosen't enjoy the work of the 'Wang', so he often skips his duties.

Kim Yesung (SJ): He is Ryeowook's roommate and the first person Ryeowook gets to knwo at his new school. Yesung often helps his new friend to get used to the schools traditions, besides that he has a hugh attraction to Ryeowook.

Choi Siwon (SJ): The students' council of Jaeneung. He always tries his best to keep everything in line and he is best friends with Kyuhyun. He gets really angry, whenever Kyuhyun skips his work as 'Wang' and always scolds him about it, which makes them look more like a mother-child pair than classmates or friends.

Lee Sungmin (SJ): Sungmin was a young student, who came to Jaeneung starting off his first year, but since his birth, he was really weak due to a sickness, which apparently affected his breathing. He was entrusted to Kyuhyun and Siwon in order to look after him and to make sure he had a worthwhile experience while he was able to attend school.

Kyungsoo (EXO): Second roommate of Ryeowook and Yesung, who often helps them with their studies, while he keeps the room clean. He is a very quiet guy, who always tries to do is best. Besides that, he seems to have a crush on Yesung.

St. Jihye Academy (blue-white uniforms):

Lee Donghae (SJ): He is the representive of Jihye Academy and a much respected and beloved member of the school like Kyuhyun, but he is more well-known at Jihye and is even oftenly called 'Prince'. He is a strong candidate to become the next 'Wang', but it seems like he dosen't want to accept the title. Donghae is a friend of Kris and has a crush on his fellow student Eunhyuk.

Lee Eunhyuk (SJ): A rather quiet boy most of the time, Eunyhuk tends to not be very outgoing. Like Ryeowook, he is a transfer student, who arrived at his second year at Jihye and immediatly joined the school's dance club together with his roommate Kris. Later he started showing intense feelings of attraction for Donghae.

Wu Kris (EXO): Eunhyuk's roommate. He is a somewhat forceful boy, who always protects his friends. He has a rebellious side, sometimes against school rules or whatever is normally accepted. He avoids human contact from time to time, besides that, he likes to criticizing students he dosen't like, for example first year students.

Han Geng (SJ): He is a very domineering, forceful and devious boy, who is also on the student council of Jihye. He often likes to take matters into his own hands, when Kyuhyun dosen't get into his way.

Park Chanyeol (EXO): The student council president of Jihye, who is a realy shrew boy. He would like to see Donghae as the next 'Wang'. As the representative of his school, he always tries to win against Siwon, the student council president of Jaeneung. Besides that, he hates Kyuhyun, but likes Donghae a lot.

Kim Heechul (SJ): Han Geng's friend and lover, who is very much like him in personality. Heechul is a snob and he sees Jihye as being superioir to the other schools of Sam. Mostly, he totally agrees to what Han Geng says and helps him with everything.

Huang Zi Tao (EXO): A first year student, who joins the school at the same time like Ryeowook. He acts mature for his age and he to have a crush on Kris, that‘s why he joined the school's music club too.

St. Chaegim Academy (red-white uniforms):

Kim Kibum & Kim Jonghyun (SHINee): The best-known couple of Chaegim Academy, who often stick to their own kind. They're good friends with Baekhyun, Yunho, Changmin and Ryeowook. While Kibum is a real diva, who tend to be egoistical and really narcisstic, Jonghyun is full of vitality and enjoys to be together with his friends. His best friend is a small dinosaur cuddle toy named Dino (디노), which he always carries around with him.

Byun Baekhyun (EXO): A free-minded, playful and natural boy, who is a member of the students' council of Chaegim, the school's cosplay club and theater club. When the representatives of the two other schools are in a fight, he often tries to arbitrate between the two parties. Baekhyun frequently helps those, who have trouble, regardless which school they attend to. He has a crush on Chanyeol.

Shim Changmin (TVXQ): Changmin seems very outgoing, hyper and is very expressive in his actions and words, not wasting any chance to introduce himself to someone new. Since he is friends with Yunho, he has an intimate relationship with him, but both of them are still uncertain about their feelings. What is certain is, that they sometimes share a bed and often are holding hands or touching.

Jung Yunho (TVXQ): He is much like Changmin, who is his best friend and roommate. Yunho is just not as clumsy as Changmin and more serious than him. Both of them are members of the schools' theater club with Baekhyun and they share each moment together.

Other Characters: (cameos)
Lee Teuk (SJ) as dorm director

Zhoumi and Henry  (SJ-M) as Ryeowook's classmates

Jinki and Minho (SHINee) as St. Jaeneung's student council member