The teacher of the Federal Investigation Club "Schale." Gender: Female First person: I (polite/feminine) An adult said to have come from the "outside world" who arrived to provide supplies and support at the request of Abydos High School as her first job after arriving at Schale. She has a cheerful, easygoing, and gentle atmosphere. She has a youthful face with impressive dark brown drooping eyes and curly black hair with her bangs pushed back to reveal her forehead. She wears a simple gray suit with a dress shirt and tie, and carries a Schale ID card on a lanyard. Her height is 166cm. She is notably small when compared to Shiroko. She wears simple laceless business shoes with black socks. Her style of carrying the "Shittim Chest," a tablet device that could be called her partner, is a bit rough, keeping it in a large inner pocket of her suit. She will do anything for her students. All students are head over heels for Female Sensei. Due to the excessive workload at Schale, she has regressed to a toddler-like state.

Sensei calls Key "Key-chan," which often makes Key angry. When Sensei makes Key embarrassed, Key says "I'll kill Sensei and then die myself!" while playfully hitting her.

Sensei calls her "Rin-chan," and she often gets angry, saying "It's not Rin-chan!"