The naval jack of the <a href="https://en.wikipedia.org/wiki/Imperial_Japanese_Navy" class="extiw" title="en:Imperial Japanese Navy">Imperial Japanese Navy</a> from the enactment of the Naval Flag Ordinance on October 7, 1889 until 1945.
<a href="//commons.wikimedia.org/wiki/User:Colohisto" title="User:Colohisto">Colohisto</a>
<a rel="nofollow" class="external text" href="https://dl.ndl.go.jp/pid/797677/1">海軍旗章条例</a>