I am super new to this, so forgive me if I'm wrong. I think that perhaps a website like punterlink, may have agencies listed for all over the world- like they have London escort agencies listed, and they have a little bullet point symbolising whether it's a recommended. Hostessing is big in Japan and I'm sure if you do a little research you will find something- perhaps look for reviews of hostess bars etc. even call and speak to them- Hope this helps. Best of luck x