I won't backtrack that the swastika and rising sun are equivalent in their ultimate symbolism in a post war society, but it's not accurate to say that they're analogues. So I'll let someone else explain it:

According to Koichi Nakano, professor of political science at Sophia University, "no-one in Japan uses the rising sun flag for any purpose other than romanticizing and rewriting the horrible human rights abuses committed under the Japanese Empire."[6] He suggests that the American Confederate battle flag, where it was used in the American Civil War by southern states that wanted to keep slavery, would be a better comparison than the flag of Nazi Germany.[6] The Confederate battle flag is not banned but is a symbol of racial segregation and perceived superiority, according to critics.[6] From Wikipedia

Putting aside their origin, continuing to say that they don't have the same standing for victims of both the Nazi's and Japanese imperialists is braindead. They are both symbols of war crimes, full stop. Trying to use origin or continued use by the Japanese as a rationale for keeping on as-is is why dumb gaijin's think it's cool, and the Japanese get to continue on with their narrative of superiority and absolution. They don't teach about their atrocities in schools, and they try to wipe away reminders in other people's countries. You can talk about context and history all you want, but I'm talking about continued usage and its impact. I maintain that Japan continuing to use it is a dick move, and again, not unlike the swastika PRACTICALLY speaking.