She is a traveling Puella Magi who collects Soul Gems from her opponents. Her targets are the Pleiades Saints.She carries two Soul Gems, the second one housing the personality and powers of a girl called Luca Souju (双樹ルカ (Souju Ruka)). Ayase acts cheerful and innocent, but only to drop her enemies' guard before letting loose her more vicious side. She is obsessed with collecting new Soul Gems, particularly the brighter ones of powerful Puella Magi. Luca is more calm and reserved, though she is just a viscous as Ayase and seems to enjoy the challenge of collecting Soul Gems as well. Both Ayase and Luca are very protective of each other's Soul Gems.