[1][2][3][4] It suggests that northern Asian 'horse-riders' influenced Japan in the 4th and 5th centuries CE.
The theory is based on horse trappings found in Japanese tombs from the Kofun Period.
Small political groups from the Early Kofun period joined under the Kawachi Court.
This made the first regional political group called "Yamato."
The Nihon Shoki, an 8th-century source, suggests a Japanese presence in Korea.
The influx of Korean goods and ideas into Japan did not result in a clear cultural change.
They say horse items appear too late to explain the early fifth-century tombs.
They question the focus on Central Asian people and the interpretation of history.
[3] Many historians propose interconnectedness between peoples across the Korean Straits without invasion or conquest.