Lee Jaejin
18 years old
The third year in high school
He's a guy who seems to be fooling around all the time but is actually extremely serious and gifted in music
He plays the bass, guitar, piano drum and can write and compose songs
His dream is to be in a band and tour through the whole world with the music he has written by himself
His father is a famous doctor and professor at Seoul National University Hospital

Kang Minhyuk
18 years old
The third year in high school
He's quite bright, playful, considerate, really sweet, but also quite a bad boy
Despite not being really great at school, he's really popular with the girls
He has at least more than 200 girl phone numbers which he all has mutual agreed to date
without being in a serious relationship
Even so, he doesn't feel too happy, as if something is lacking
He relieves his stress by playing the drum at a club
 

Park Jaehyung
17 years old
Second year of high school
Loves magic tricks and is quite clumsy in a cute way
He's really smart and always has those nerdy glasses on
He's the perfect son that all mothers want and his parents has high hopes for him as well
He himself the other side got into a slump because he really has no idea what he wants to do in the future

Cha Hun
17 years old
Second year of high school
He seems really cold from the outside and barely talks
Since he's not so talkative, he often gets misunderstood as being rude
Is really good with computers and games and has the best grades of his school
For some reasons he always say that his guitar his only friend is
Even though Lee Hyunwoo is known to be his best friend by everyone and also the one of the few he actually talks to

Jung Soojung
18 years old
Jaejin's classmate since middle school
She's a bit bossy, tomboyish and is quite the tsundere type
She supports everything Jaejin does, despite not always being the smartest decisions

Lee Hyunwoo
16 years old
A genius who has skipped quite some classes
In order to think clearly what he wants to learn in the future, he's taken a gap year
Cha Hun's best friend and sometimes joins classes with him despite having graduated already
Different than Cha Hun, he's really talkative and lively
Stopped contacting him suddenly for unknown reasons

Park Jiyeon
16 years old
First year of high school
Hyunwoo's childhood friend
She's an adorable girl that everyone likes
Has a crush on Hyunwoo
She does everything she can in order to hang out with the two boys, especially Hyunwoo
Blames Cha Hun of Lee Hyunwoo's disappearance