noun
rising sun flag
Refers specifically to the flag with a red sun and rays, historically used by the Japanese military and now by the Japan Maritime Self-Defense Force. The term is less common in everyday conversation than 旭日旗 (きょくじつき).
旭旗は、かつて日本軍が使用していた旗です。
The rising sun flag is a flag that was once used by the Japanese military.