japanese flag
On danbooru, the word of "Japanese flag" means almost same as the "旭日旗 (Kyokujitsu-ki, the Rising Sun flag)", which was the military flag of Japan used by the Imperial Japanese Navy and the Imperial Japanese Army.
While the national flag of Japan has only a red circle, the Rising Sun flag is a compound of a red circle and sun rays.
See Also
- Wikipedia article: 旭日旗 (Rising Sun flag)
- Wikipedia article: 日章旗 (Nisshou-ki, the national flag of Japan)