Most languages deal with that problem by simply taking names as they are, sometimes transliterating to fit the alphabet available. It doesn't matter if I'm speaking dutch or english, my name is unchanged.
The only wide exception to this tends to be country names which mostly seem to get a global and a local name. There's no real reason to do this when using toki-pona.
you could go for constructs like "ma pi suno tewi sewi" which'd translate to "land of the rising sun" or more literally "land of the sun going up" but I fail to see the point. Any toki pona ''native'' would be able to read and pronounce "japan" since all the letters are available in the toki pona alphabet, the pronunciation even matches well enough. If someone doesn't know japan they won't know what "land of the rising sun" refers to and you'd need to reach for more descriptive language in any case.
Disclaimer: my grasp of toki pona grammar is tenuous at best, I'm sure there's better translations for "land of the rising sun".
The official Toki Pona book details a procedure for word-borrowing (and also has a suggested list of translated country names). The online the only source is a way more linguistically-flavoured article by the creator of the language, that goes into way more detail than the official book itself:
The only wide exception to this tends to be country names which mostly seem to get a global and a local name. There's no real reason to do this when using toki-pona.
you could go for constructs like "ma pi suno tewi sewi" which'd translate to "land of the rising sun" or more literally "land of the sun going up" but I fail to see the point. Any toki pona ''native'' would be able to read and pronounce "japan" since all the letters are available in the toki pona alphabet, the pronunciation even matches well enough. If someone doesn't know japan they won't know what "land of the rising sun" refers to and you'd need to reach for more descriptive language in any case.
Disclaimer: my grasp of toki pona grammar is tenuous at best, I'm sure there's better translations for "land of the rising sun".