The Star Army of Yamatai used a tricorne type hat with its duty uniforms from YE 21 to YE 32. It was replaced by the Star Army Cap, Type 32.

The shape of the tricorne was felt to be ideal for Nekovalkyrja ears.

The cap was three-sided and made of felt or beaver fur. It was typically black, but was also made and authorized in white, dark gray, tan, or brown. The enlisted version had a red trim on the top while the officer version had white trim. There were also gold-trimmed versions for admirals and blue-trimmed versions for warrant officers.

Rank pins were worn on the left front side of the cap.