Principal character. She is the violin in the quartet. She's an innocent girl but nice and agreable. She loves music in general and is extremely good at playing violin. She hides a big secret, however.

He's the violonchelo in the quartet. He's not very popular, is a hard student and one of the best in school. He also plays the piano and is the author of a music piece titled, "Quartet Game."

He's the second violin in the quartet. He's one of the most popular guys in school and a real playboy who loves flirting with girls.

She plays the viola in the quartet. She's a pretty girl but very rebellious. She goes out with motorists and she has an impressive one herself. She's a "Madoka" in Yoshizumi's style.

He's the professor who is incharge of training the quartet and making sure they will be ready for the concert. He's the one who decides which piece they must play and knows Emi for a long time. His intentions, even though they don't seem bad, are pretty dark.

He's a famous Japanese violinist known in the whole world. He decides to return to Japan after a long time and he's going to receive a homage concert in the school where Emi and Co. study. At the start, the quartet is formed to honor him.