OVA
Description
Hailing from China, Ku Fei attends Mahora Academy's Class 3-A. Born March 16th and currently 16 years old, she stands 160 cm tall with blonde hair, green eyes, and distinctive body measurements of 78-56-80 cm. Her light brown skin tone suggests tropical origins atypical for Chinese characters. Academically challenged primarily by limited Japanese proficiency, she joins the underperforming Baka Rangers as "Baka Yellow."

Ku Fei works part-time at the Chao Bao Zi restaurant, owned by her close friend and classmate Chao Lingshen. There, she frequently consumes nikuman and serves as a test subject for Chao's inventions. Her defining trait is exceptional martial arts prowess. She specializes in powerful, rough Chinese Kung Fu combined with complex staff maneuvers and misdirection. Ambidextrous, she alternates offense and defense seamlessly between her staff and sheath; this style leaves defensive openings but compensates with unpredictable counterattacks.

This expertise leads her to train Negi Springfield post-Kyoto. Adopting the persona "Ku Roushi"—a wise master with a white beard and traditional attire—she instructs him in ki control and combat fundamentals, enabling him to pass Evangeline A.K. McDowell's trials. During the Kyoto trip, she participates in the "Kiss Negi" contest, kissing only a paper clone which results in an ineffective pactio card. Later, she assists during the Hermann incident by rescuing Chizuru Naba. In the Mahora Festival martial arts tournament, she defeats Mana Tatsumiya after a brutal fight that fractures her arm, forcing her withdrawal; Ku:Nel Sanders later heals the injury. Despite her closeness to Chao, Chao conceals her time-travel plans, and Ku Fei only learns of Chao's departure shortly before the farewell party.

In the Summer OVA, Ku Fei appears during the beach resort sequence, engaging in recreational activities like playing frisbee with Makie, Chizuru, Natsumi, and Kaede, showcasing her physical agility. Her familial connections include distant descendants: Alysia Fei (20 generations removed) and Chao Lingshen (6 generations removed).