The reconstructed Middle Chinese pronunciation for 日本 is /ȵiɪt̚ puən/. In some languages, such as Japanese, the ȵ became an n. In others, such as Mandarin, it d

The reconstructed Middle Chinese pronunciation for 日本 is /ȵiɪt̚ puən/. In some languages, such as Japanese, the ȵ became an n. In others, such as Mandarin, it denasalized to a fricative like ʐ̩ instead. The etymology for English "Japan" /dʒəˈpæn/ is apparently Portuguese "Japão" /ʒɐ.ˈpɐ̃w̃/ via Malay "Jepun" /d͡ʒəpon/, via Min Nan 日本 (Ji̍t-pún) /ʑit̚⁴⁻³² pun⁴¹/ which itself is probably a loan (using Min readings of the characters), since the Min languages split off the Chinese branch before 日本 came to be used for Japan. https://en.wiktionary.org/wiki/%E6%97%A5%E6%9C%AC#Pronunciation https://en.wiktionary.org/wiki/%E6%97%A5%E6%9C%AC#Pronunciat...