An analytics officer at Ratatoskr—and also the assistant homeroom teacher for Shido's class. She appears to suffer from insomnia and looks drowsy at all times. She may speak and act extremely cryptically, but she has a familiar nickname for Shido: "Shin."

Shido's homeroom teacher. Her students affectionately refer to her as "Tama-chan." Though she looks as young as her students at first glance, she is actually 29 years old. She's currently single and desperate to get married.

Shido's classmate and one of his few male friends. His abiding interest in the ladies bleeds out into his words and attitude, which may explain why the ladies never show much interest in him.

Shido's biological sister, though they were separated when they were very young. She is currently under Ratatoskr's protection and doesn't live at Shido's residence. She's hostile towards Kurumi and often warns her brother about her.