One of the main protagonists in the story and an HWT pilot. Mai was a transfer pilot to the 5121st Platoon. She initially separated herself from everyone in the division but formed a friendship with Nonomi and eventually, the whole female crew of the platoon. She first saves Mibuya and Hayami when they were in the effective range of the PBE. Afterwards, she gained the gratitude of Hayami and a slight rivalry with Mibuya. Her skills as an HWT pilot are at near perfection. However, her teamwork is as relatively poor as her communication skills. Later on, it is revealed that Mai is the daughter of the head of Shibamura Industries. Despite that, she tries to lead a normal life and care for Nonomi; thinking she is responsible for her condition. When Hayami and Mai were stranded, she revealed why she came to join the army despite her status as being the daughter of the head of Shibamura. When she was in her old high school, she became infatuated with an elite HWT pilot but never admitted her feelings to him as he died fighting the Genjyu. Holding a grudge against the Genjyu, she trained to be an elite pilot and was eventually transferred to the 5121st platoon. After Hayami saves her, Mai begins to be infatuated with him but again, she is too shy to admit her true feelings to him.