yes, Ainu discovered japan.

nihon

They are the ainu

The Ainu walked and traveled by canoe

John Batchelor has written:

'The Ainu of Japan' -- subject- s -: Accessible book, Ainu, Social life and customs

'An Ainu-English-Japanese dictionary' -- subject- s -: Ainu language, Dictionaries, English language, Japanese language, Polyglot

'The Ainu and their folk-lore' -- subject- s -: Accessible book, Ainu, Folklore

'The pit-dwellers of Hokkaido and Ainu place-names considered'

Hitoshi Watanabe has written:

'The Ainu ecosystem: environment and group structure' -- subject(s): Ainu

'Jomon-shiki kaisoka shakai (Jinruishi sosho)'

'The Ainu' -- subject(s): Ainu