Ranchu, a dorsal-less fin has round head and body structure. Aside from well displaying the elegant of the royalty (generally, distinguished as the king of gold fish), it also maintains the classical beauty of a traditional gold fish. It has a board backbone that stretches downward at the end. This enhances the stunning attraction of the fish.

The Japanese has contributed heavily to the success of ranchu popularity, especially in the top-view. There are as many as 50 ranchu clubs in Japan. Some clubs would held an internal competition during the late October period before the AJRC competition on 3th November.

For the Tosai (less than 1 year fish) are divided into two catalogues, the Tosai (Big) and Tosai (Small). These are some of the competition winners.