Ku-ga imo is a little-known yam indigenous to the Ryukyu Arc. "Kuga" refers to the male testicles in Okinawan language. The yam is around 5 cm long, light brown in color, and covered in thin, short roots. Ku-ga imo is delicate to cold and needs a lot of attention while cultivation.
It is currently cultivated in the middle and northern regions of Okinawa Island and harvested between December and the end of February. In recent years, commercial varieties that are simpler to grow have been introduced, and the number of Ku-ga imo farmers has decreased. In recent years, efforts have been made to safeguard the Ku-ga imo and keep its production going.

It is sometimes grated and used as a binder for fish paste, eaten as a garnish for Okinawan soba noodles, and also becomes a good luck charm in the traditional New Year's soup.

It has been wild in the forests of Okinawa Island's center and northern regions since the Ryukyu Dynasty. Unfortunately, overdevelopment has made it harder to find them in natural fields. Nowadays, only a few farmers cultivate it in tiny numbers; therefore, it is not widely available in the market.