Moving to Japan as an ethnic Korean

I am currently a college student studying in the US and I grew up outside Korea for the most part although I was born there. I am interested in potentially moving to Japan at some point as I want to experience different cultures before settling back in the states (or maybe staying there who knows). I visited Kyoto around four years ago as a tourist and I really loved it. Still, I think I would prefer living in a more global city like Tokyo or Osaka with a better infrastructure.

I’ve been learning Japanese for about three months now, and thanks to my language background (I speak Korean at home), I’ve found it relatively easy to pick up. That said, I wouldn’t call myself fluent yet — there’s still a long way to go. Assuming I can somehow reach a decent level of proficiency in the language, do you think I would enjoy living in Japan, especially in a big city?

Also, as someone who's been to Seoul a number of times, I’m curious about how major cities in Japan like Tokyo compare to Seoul. I’d love to hear perspectives from people who have lived or traveled extensively in both countries.