An article during July, in 645 of the "Nihonshoki" (Chronicles of Japan) contains an article where `myojin (a gracious deity) Gyou (the reign of the Emperor) Japanese Emperor' was shown to the envoys from Goguryeo (kingdom of Korea) or Kudara (Baekje, Paekche), which was the first case of country name, `Nihon' (Japan), which was used in Japan.
『日本書紀』大化元年七月の条に高句麗や百済の使者に「明神御宇日本天皇」と示したという記事があり、日本における「日本」という国号の最初の使用例となっている。