Japanese plate - Keizan

Hello,

I bought this Japanese plate a month ago. I am having a hard time attributing it. The first to characters together are keizan. What period could this be? Is this Kobayashi Keizan? What period does this come from? What is the seal-like thing and the third character on the back? The seal like thing seems to contain kei.
A lot of questions! Thanks in advance,
Jonathan

 

Google lens is coming up with Arita ware items with similar marks. The circle mark is a mons or crest mark. Looks fairly modern. Sorry, that's all I've got. but it's a nice plate.

 

Thanks! Ill see if someone else has something more to say

EDIT: I figured out the last character is a stylized 作. So 圭山作 (Keizan-saku). So roughly translated made by Keizan.

 

This may relate: https://arita-keizan.jp/en/

 

Thanks, however i think this is not possible because they write themselves as 渓山, which differs from 圭山. Maybe an earlier family member before the contemporary kiln was established.

 

Well, the only Japanese character I recognize is the one for nine which is usually on kutani pieces, LOL. But it appears it is an Arita production.