Japan is a linguistic minefield and defies generalization. In Ainu 'nanna' is mother and in Okinawan it's 'anma'. In Old Japanese there's 'haha' (and variants -

Japan is a linguistic minefield and defies generalization. In Ainu 'nanna' is mother and in Okinawan it's 'anma'. In Old Japanese there's 'haha' (and variants - 'papa' appears to have been prevelent in Old Japanese, see link in cousin post) and 'amo'. Also note: while 'mama' is a loanword it's overwhelmingly what babies call their mothers in Japan i.e. it has outcompeted other words likely for the same reasons as said in the article.