(Touhou 7,9) Gold eyes, short blond hair, always seen with her violin floating nearby. Band uniform is black, with white and red trim. Her hat has a red crescent moon decoration at the peak.
(Touhou 9, alternative outfit) Same as above, except her dress is black.
Merlin
(Touhou 7,9) Blue eyes, wavy light-blue hair, always seen with her trumpet floating nearby. Band uniform is pink, with blue and black trim. Her hat has a blue sun decoration at the peak.
(Touhou 9, alternative outfit) Same as above, except her dress is cyan, and her trumpet is silver.
Lyrica
(Touhou 7,9) Brown eyes, short light brown hair, always seen with her winged keyboard floating nearby. The keyboard has "L.P." (her initials) written. Band uniform is red, with pink and black trim. Her hat has a green shooting star decoration at the peak.
(Touhou 9, alternative outfit) Same as above, except her hair is lighter in color, clothes are yellow, and her hat's shooting star is blue. Keyboard has now "Prismriver" written on it.
During the events of Perfect Cherry Blossom, the three Prismriver Sisters are preparing to play a concert for the flower viewing at Yuyuko's mansion. They attempt to stop the player from entering the Netherworld together, and the progression of the battle is affected by which sister the player decides to focus on attacking during their first spell card. The dialog they bounce back and forth between each other and the player is actually quite comical, and shows their very individual personalities. Lunasa Prismriver is mature and mellow, Merlin Prismriver is happy-go-lucky and clueless, and Lyrica Prismriver is a sly smart-aleck.
In Phantasmagoria of Flower View, Lyrica, the youngest of the three, goes off on her own to collect material for her songs. She's not really interested in solving the flower incident and would rather focus on her performance, but unknown to her, she's not alone.