According to the Fu Mulberry Chronicle,

What is Hachiman?

Japan emperors, the 16th Emperor Ōjin, declared that they would enshrine a foreign god called Hachiman in various countries.

There is a place called Ogawa Yawata Shrine in Wakayama Prefecture, and

According to the company biography there,

From 540 to 570, the prince of Emperor Kinmei moved from Yamato Province to Kii Province and sat there.　　

There is a manuscript of the Great Sutra by Xuanzang? is in the collection.

Brought in by Koreans or Chinese?

In my opinion,

In terms of timing, before the Kinashi clan of Zenkoji Temple and Yoshimitsu Tanda went from Namba to meet Emperor Kinmei,

It is presumed to have been left behind by calling at a port in Kii Province.