My daughter likes anime and we just looked up the word "ponyo" as there is a film of this title.We found that in Japan the word means chubby or stout but without the negative connotations we have for those words in England.Can anyone tell me the connotations these words hold in Japan?
I can't answer this directly, but different words have different connotations even in English. Fat, obese, fuller figure, bucket of lard, stout... So it might for instance imply something like "cuddly".