Megu Tsuyumine

Zokugaku's manager and trainer, Megu Tsuyumine is a rough, no-nonsense woman who carries a wooden practice sword and is not above torturing the team members in order to get them to train harder. Some of her known tactics are towing players behind her motorcycle, hitting them between the legs with her wooden sword, and making them carry their motorcycles on their backs, with herself sitting on Habashira's motorcycle. She rules the team with an iron fist and even Habashira is afraid of her. However, she and Habashira are good companions who share a great deal of trust and understanding. She refers to him as "Rui," his given name, instead of Habashira-kun, which is Japanese custom even for close friends, and especially for women, demonstrating their closeness. Like Habashira, she is a second-year student.

(Source: Eyeshield 21 Wikia)