A timid shrine maiden who was convinced by her lover to become an idol with her. She works at a shrine right outside the city, rumoured to manifest cat spirits who lead people to their inevitable fate. After meeting her lover through these spirits, she realized that perhaps becoming an idol with her will guide them towards their fate: to become a famous idol group. After a while of hearing her rants and lectures about being an idol, her determination to strive towards her fate becomes never questioned. In her heart, she believed that as long as she is with her lover, things will work out as needed. However as a young adult, living in her apartment with her girlfriend and working part-time jobs as well as taking college classes, it is no easy feat. Most of her concern was paying rent until a famous idol came along to sweep them off their feet.

Ayaka is known to be the "glue" of PRIMUS, as she would always be the mediator between Maeko and Paju's arguments, whether intentionally or unintentionally. Her role in PRIMUS is the center, as Maeko willingly gave the role to her because of her serene voice, blending the other two's voices together perfectly. She honors Paju as a rolemodel, as well as her lover's relative. Due to this, Paju and Ayaka became close friends, as Paju calls Ayaka his favorite student compared to the "always angry" Maeko. With a famous idol to teach them the ropes, she hopes this leads them closer to their dream... while also closer to not worry about rent.