Lunasa is the eldest of the Prismriver sisters and the leader of their ensemble. With a talent for stringed instruments, she loves to play the violin. She isn't always recognized as the leader, perhaps due to her slightly dour nature, but whether it be organizing their performances or instructing her younger sisters, it seems like she more than fulfills that role.

Merlin is the second eldest of the Prismriver sisters and the crowd favorite of their ensemble. With a talent for wind instruments, she loves to play the trumpet. She often takes center stage (not only at performances) and has a bright and cheerful personality. This often leads to people mistaking her for the ensemble's leader.

Lyrica is the third eldest of the Prismriver sisters and organizes their ensemble. There's no instrument she can't play, but she loves the keyboard. Smoothly navigating her way through life, she's the only one of the three who seldom acts alone, and is content to ride on her sisters' coattails.

There's a room in a large mansion filled with items seldom seen in Gensokyo that come from the outside world. Even the air itself seems somehow special. Today, the room serves as one of the trio's practice rooms, but in a time gone by, four used to run around and play here. If you listen carefully... Did you hear it? Just now, you heard their gleeful giggles, didn't you?

They play any time, any day. All it takes is a moment after the piece ends. Just like that, the trio's thoughts align, and the next piece is decided. They dedicate it to a young girl, one more important to them than anything. She was a solemn girl, so to stave off her loneliness, the trio play with as much energy and vibrancy as they can muster. It reminds them of the days when they played together as four, back before they lost their youngest sister.