Kim Kaphwan was named after then chairman of the Korean development studio, Viccom. Chairman Kim was responsible for the Korean imports of SNK arcade cabinets and lent his name, as well as the names of his family members, to ensure SNK's Korean characters had authentic Korean names. Like his game counterpart, he was also a Taekwondo practitioner.
During the early development of Fatal Fury 2, SNK had two different ideas for Japanese characters: a male ninja named Ninja Master and a female idol. Ninja Master had been around 60% completed before being scrapped. However, many of his design elements were used for the design of the idol character, who would eventually become Mai Shiranui. The design for her "tail" was taken from his long scarf.
According to an issue of Neo Geo Freak, Mai's bust was modeled on Fumie Hosokawa and her buttocks on Ai Iijima; both women were famous idols at the time.