Continuing tradition

Most, if not all of you, will recognise this flag. It is the naval ensign of the Japan Maritime Self-Defense Force (JMSDF). It was also the naval ensign of the Imperial Japanese Navy (IJN). An interesting thing to note is that while the Japan Ground Self-Defense Force (JGSDF) was not a continuation of the Imperial Japanese Army, the JMSDF was built upon the foundations left behind by the IJN. When World War 2 ended, the IJN was not fully disbanded, since the occupation forces needed the IJN's minesweepers to continue to help clear the mined waters in and around Japan. When the Korean War broke out, these minesweepers were sent to help clear the mined waters around the landing beaches of Korea. The remnants of the IJN became the base upon which the JMSDF was built when Japan was allowed to form up a policing force to augment her ability to defend her, as US forces were drawn into the Korean War.

As with all naval and government ships, JMSDF ships are allowed to fly an ensign to identify themselves as being ships in the service of the JMSDF and thus represent Japanese sovereignty. When choosing the design for the JMSDF naval ensign, the designer drew up an exact replica of the IJN's naval ensign, the Rising Sun flag. It was eventually accepted by then-Prime Minister Yoshida Shigeru as the JMSDF naval ensign. He said, "There is no place in the world in which this flag is not recognised. No matter where it may be, you will recognise this as a Japanese ship at one look. I hope that the JMSDF will continue to uphold the fine naval traditions and do its very best to protect the maritime nation of Japan."(「世界中でこの旗を知らぬ国はない。どこの海に在っても日本の艦であることが一目瞭然で誠に結構だ。旧海軍の良い伝統を受け継いで、海国日本の護りをしっかりやってもらいたい。」Quote taken from here.)

This is just an example of one IJN tradition that is continued on by the JMSDF.

And if you had recognised the flag even without reading the whole blog post, you would have proven PM Yoshida correct.