Yiyi Xu

Yiyi Xu is a professor and scientist at the Alltale Management Facility who works alongside Tsunehisa Senko and Naomi Katagaki. Serious, hardworking and friendly with her colleagues, she normally values rules, though Senko's habits gradually encourage her to bend them on occasion.

Yiyi has a habit of entering other people's rooms and thoroughly cleaning them. When worried, she frequently slips into her native language.