No one complained about the use of the Rising Sun Flag for nearly 70 years after the war then Koreans suddenly started making a fuss about it to defame Japan around 2012. In fact, Koreans were using the RSF & RSF-like design themselves.

It's called anti-Japanese propaganda.

The Rising Sun Flag is still used as the naval ensign of the Japanese Navy to this day. It's the OFFICIAL flag of Japan. It's nothing like a Nazi symbol.

Don't fall for Korea's anti-Japanese propaganda.

Korea's Rising Sun Flag claim was fabricated. They made it up to protect their football (soccer ) player and save face.

https://thescottishsun.co.uk/archives/news/45754/cheeky-monki/
https://en.wikipedia.org/wiki/Ki_Sung-yueng

FYI, there were no Rising Sun Flag in the stand.
Ki Sung-yueng lied (twice) to get out of a mess.

Asians have no issue with the Rising Sun Flag. Korea is the only one to complain about the flag and it's anti-Japanese propaganda, period.

"Rising Sun Flag = Nazi symbol" was fabricated by Koreans to hate on Japan and they started spreading the lie in 2012.
Look up "Rising Sun Flag = Nazi flag" then you'll notice that 99% of articles, blogs, tweets and comments of their false claim are all posted after 2011.

2009 WBC Final

KOR vs JPN

This baseball game was SO HUGE and yet Koreans said nothing about a Japanese spectator waving the Rising Sun Flag because it wasn't even an issue back then. Koreans made shit up to defame Japan and started spreading anti-Japanese propaganda in 2012.

The Rising Sun Flag has existed since 1600's. It has been used as a traditional national symbol of Japan since the Edo period (1603 CE).
That's why the Japanese sometimes use the Rising Sun Flag to represent Japan at sporting events, etc.

Also, the design of the Rising Sun Flag is widely used throughout Japan, such as good catch flags used by fishermen, celebratory flags for childbirth and seasonal festivities. People need to understand the Rising Sun Flag is not just a war flag in Japan.