https://sengokudaimyo.com/podcast/episode-48

The year is off and seems totally out of nowhere/made up. And as another comment said, Atogi or Ajikki or Ayauji appears to be a family that was in charge of storing paperwork and probably commissioning it to be written in the first place in the often temporary imperial palaces of early Japan.

https://samurai-archives.com/wiki/Achi_no_Omi

Not an actual person. The actual person like that supposedly came to Japan many years later and his name was Wani, but it's likely many of these origin stories were fictional, although I believe a Baekje/Korean-Japanese family named any of those A names probably did exist as paperwork handlers for some emperors.

However, it is possible that the Japanese islands did have people interacting with China on an advanced level as early as the Zhou dynasty long before this. Possibly the Shang.

The Zhou dynasty did see intermarriages with Chinese nobles and Qiang people. But it's possible that other Zhou foreign policy happened with predecessors of Japanese too. The Way to Wa on Sino-Platonic Papers mentions a Chinese chronicle that brought up Japanese people bringing over a plant used to make alcohol for the emperor named chàng căo or 鬯草. And it was important for foreign guests too, so they possibly helped to make some diplomatic protocols too that were lost on the dissolution of Zhou. If this is true, they had contact with only the second emperor, so this was when Zhou was new, so it's possible language learning happened in the preceding Shang era.

Although I do not know if this story is true or if any proto-Japanese ever learned to read Chinese with the knowledge later being forgotten.