Seheon is the youngest son of a Music Professor and his older Brother is gifted when it comes to music. His Father is prejudiced about music. He feels that only Classical Music is worth playing. Seheon plate the Piano and he loves Jazz Music. His Father has him practicing playing Classical almost every waking hour. With the exception of School Work, eating and sleep. He transfers to a special High School, in his Sophomore year, after being home schooled. There he eventually meets Seyi, who also loves Jazz. Things between the two of them don't start off well. Seyi tells Seheon that if he ever finds Seheon playing the Piano in that room again he will kill him.
A little while later we meet Juha. He is 1-2 years ahead of Seheon and Seyi in School. He has an axe to grind with Seyi. After noticing Seyi seems to care about Seheon he decides he will get "friendly" with Seheon to get even with Seyi. As time goes on Seyi stops being antagonistic towards Seheon. Seheon starts to develop feelings for Seyi due to his kindness. One day after Seyi takes care of a cut on Seheon's hand, Seheon leans over and kisses Seyi. Seyi wipes off his mouth and walks out. After sometime and introspection Seyi comes to realize he does like Seheon.
Personally, while I feel this a good Drama and definitely worth watching, I feel it was too short and they need to spend some more time on character development. After Seheon returns home after running away from home, his Father is furious with him and starts a fight. You can see that his Father does love him and was worried about him but can't express it properly. I would like to have seen what made him that way. Seheon's older cares about him and tries to always act as a go between with Dad and Seheon. I would also like to have seen why his Father lets him practice Jazz and enter the Festival. I would also liked to it if they showed a little of Juha 's background and why originally a bully. I feel that they should have added about 2 more episodes. To flesh out the characters. It felt a little rushed towards the end. It is worth rewatching and hopefully they will make a season 2 to give us a little more backstory for the characters and maybe give us more time with the 2nd Couple, Doyoon and Juha.