Potential career paths in Japan?

Hi everyone, before I start, here is a TLDR:
Uni student graduating in July 2026, UK based, working full time alongside university operating CNC Zund machines (niche industry), can't find any companies willing to sponsor for a skill set like mine. Any suggestions?

Now, to get into the more specific areas, I want to move to Japan as soon as possible after graduation for the simple reason being that my girlfriend is Japanese and she would want me to move there. (I also love Japan, visited many times and actively studying the language)

I am studying Business Management full time at university alongside my full time job operating Zund CNC machinery. Its a very niche industry, and I am more on the sales side of the company, selling the machines to customers and testing materials etc. I cannot find any sort of job in japan that would be interested in this skill set and I am starting to get really demotivated.

I also have the option of going into sales, with my background in business and experience with customers and selling machinery, however i would require excellent Japanese skills and i am simply not there yet, maybe very rough N4 level right now. (Can have daily talks in Japanese perfectly because of gf but i lack a lot of vocabulary and business context)

What would be the ideal path to go down, I feel CNC might be easier language wise, but I can't find any opportunities, should I do language school for a year in japan to at least be with my gf and prepare for a sales position?

Please give me any advice you might have.

よろしくお願いします