The story centers on the main character, Mei Takahara, who lives with her older stepbrother named Natsu whom she has fallen in love with. The plot thickens when a friend of the family whose parents have died comes to live with the siblings. Mei struggles with the complications of her feelings with Natsu and the newcomer to her home who also develops feelings for him.
Mei is in 8th grade and is the president of her school band. She plays the saxophone. She lives alone with her brother Natsu. However, Mei and Natsu are not related by blood and Mei is in love with him. But she gave up on him when Natsu started dating Melvina. Later she asks Shuu out, trying to forget Natsu.
Mei's brother and a genius musician, already famous at the age of 17. He can play a number of instruments, but spends most of his time writing songs. He is in great demand and is often overworked. He starts dating Mel, but moves out when he finds out that Mel and he are half-siblings.
Melvina "Mel" Molan
Now living with Mei and Natsu because her parents died. She is good-looking and has a beautiful singing voice. She starts dating Natsu, but they break up when they find out they are half-siblings.
Shuu is in 9th grade and plays the drums. He has a part-time job at a nearby restaurant. He attends the same school as Mei, but he hasn't shown up since around the end of his first year. The reason for him not coming to school is unknown.
Mei's best friend and vice-president of the band. She is always supportive of Mei.
Mei's mother. She married Natsu's father but later divorced him. Tends to be blunt.
Natsu's father. Rather irresponsible and "adopted" Melvina, only to dump her off onto Natsu. He moved back to Australia in an attempt to jump-start his failing business. He is Mel's father. Mel's mother saved him when he tried to commit suicide.