looking for a sponsor so i can get a working visa

I (F18) want to live in Japan for a few years to join my Boyfriend (M18) while he is in language school, but i don’t have the funds to go to language school due to it being £9000. For a working visa I am aware i need £2000 in my bank account and other things, so my plan is to go out there with him, but have a full time or part time job while i’m learning how to 3d model since that’s what i want to do as a career (not for when i move because i’m not planning to do it just yet). My bf is going to Japan in March 2026. So i need to find a sponsor first, then sort out my working visa after i’ve got a sponsor. I need a bit of help trying to find a job or company that could sponsor me. I have a years worth of customer service, I’ve worked as a waitress and a cashier and am currently working in a manufacturing job up until December. I’ve been learning a bit of Japanese for the past 70 days but i will also learn more. A relative of mine said Hostels might be a good option for someone like me or working in bars. If anyone knows any good companies or jobs in Tokyo or around Tokyo it would mean so much.