Chihiro Senkawa works as the secretary for the Producer at 346 Production. She manages administrative duties, paperwork, phone calls, and offers career guidance to new idols. Her appearance varies, sometimes showing her as just out of her teens and other times slightly older, always in conservative yet figure-flattering attire. Standing at 154 cm tall makes her the franchise's shortest secretary, with light brown hair, bright red eyes, blood type A, and measurements of 82-58-84 cm.

Her personality is upbeat, positive, and professionally excitable. She displays unwavering loyalty to the Producer, offering encouragement during setbacks and assuring constant support. She organizes office activities like parties and enjoys cosplay as a hobby. Her duties include explaining game mechanics and mission objectives to players, running tutorials, and overseeing office operations when the Producer is absent, commanding respect from the idols in that role.

Her dynamic with the Producer features moments of subtle camaraderie, like providing consolation on Valentine's Day if he receives no gifts or hinting at concern over excessive idol attention. A minigame depicts playful interactions where the Producer tries to hit her with a water gun, forcing her to dodge. Though fans express interest in her becoming an idol, she remains a non-playable character ineligible for in-game voting. Fan discussions occasionally pair her with Mishiro despite no canonical interactions.

Notably, she starred in an April Fools' Day event, performing "Onegai! Cinderella" with a dedicated 3D model, revealing unexpected idol potential. She shares a birthday, November 28, with Sora Nonomura and hails from Tokyo like several idols.