A medical intern working at Yamamura University Hospital in Sagami City. She passionately admires Shina Ninomiya. Despite her busy schedule, she also works part-time at Iris Corporation. It's not because she's in financial trouble—it's to see Shina more often, of course.

She's been involved as a debugger since the development of World's Odyssey, and there's even a rumor that the popular character Lily Hopes, originally designed with blonde hair, was changed to look more like Yurisa. It seems Shina recognizes her as one of her important partners.

As for Ms. Yamamura herself, she holds some strong feelings for Shina that go beyond just being coworkers. Shina, aware of this, skillfully postpones giving her a real answer. Though handing over a spare key to her apartment may have been a mistake—just saying, haha!

Sayaka's direct supervisor is Yurisa Yamamura. She seems to be good at looking after her team. While she views Sayaka as a rival, she still stands with everyone to face the world's looming threats!