Height 166 cm (5' 6") Nationality Japanese Affiliation Hakuryo Hiiragi, United Nations Army Yokohama Base, IJA/MDF 1st Battalion Rank Sergeant, Major TSF Type-77 Gekishin, Type-94 Shiranui English teacher at Hakuryo and class 3-B's homeroom teacher, called "Marimo-chan" by Takeru. She can be ditzy and a bit of a nag, but has a gentle personality. Popular with both boys and girls, Marimo is loved by all of her students. She became a teacher along with her best friend from Hakuryo Hiiragi, Yuuko. She's always been somewhat of Yuuko's plaything as the subject of her jokes and schemes, and she often makes fun of how familiar Takeru treats Marimo. In Alternative, Marimo is an instructor for the UN at Yokohama Base. Extremely strict and serious in hopes that the people she teaches don't die, she gained nicknames like "Mad Dog" and "Demon Sergeant" for how she treated her students. Under the tough exterior, she cares for her students all the same. She once had a dream to become a teacher, but when the BETA came closer and Japan's became obsessed with military based education, she dropped out of college to become a soldier. Eventually, she decided proper education was the essential for pilots to survive, and became an instructor at her old classmate and best friend Professor Kouzuki's recommendation, Yokohama Base.

Spoiler

Major in the IJA and commander of the IMJDF's 1st Battalion, stationed in Seattle. Along with being one of the highest ranking soldiers in Seattle, Marimo is involved in political matters, such as negotiations with the U.S. regarding the Japanese residential area's management, a constant source of worry and stress for her.