The F-Kunoichi Kai is based on "unofficial" art work of the "F-9ノ1" drawn by Shinya Terashima, a mechanical designer working on Gundam Build Divers​, based on a joke between himself and Build Divers​' director, Shinya Watada. Thinking that the idea was too good to let go to waste, Terashima made art of it which Director Watada is said to have liked, giving it a semi-official status as the Gunpla used by Aya Fujisawa in middle school, before she made the RX-Zeromaru.

The F-Kunoichi's name and concept is based on wordplay with the Japanese word kunoichi (くノ一?), a term contemporarily used for a female ninja, which contains similar sounds as the numbers nine (九 Kyū?) and one (一 Ichi?) in Japanese, the same numbers used in the Gundam F91.