Struggling to wrap my head around EOR Agencies and how it could work

I have searched here and seen some posts but there's a few ways the EOR agencies work it seems so I'm just asking for some clarity.

I have my own business that operates remotely, I have had Japanese clients in the past and there are industry events etc. in Japan relevant to my business, from what i understand I can use an EOR agency, I will be paid through them and then in theory could get a work visa?

Is this possible as I'm essentially hiring myself – no company etc. will be hiring me.

If it's possible I will focus on Japanese market, the business manager visa seems very difficult and expensive so I'm wondering if the EOR route is viable and more plausible. TIA