You edited you post long after I posted my response.

Who mentioned Africa or South America? The two most populous nations in the world are China and India! Those need visas in advance.

And unless you're trying to maximise air miles you should have a look at a map of Asia Pacific - your routing is going a very long way round!

You are aware that the only people with tattoos in Japan are gangsters or their concubines (who are tattooed as a sort of ownership mark)? You'll get some strange looks there. (And getting around unless you speak the language is non-trivial)