The size of the metropolis, the number of people, or something else?

For me personally Tokyo is fucking magical but I also grew up in a town of less than 20,000 residents in Ohio.

Not every country in the world. Taiwan is missing.

It’s not a place that you mentioned, but maybe try Taiwan? I used to live in Taipei, it’ll be cheaper than Seoul, and maybe scratch a bit of that Chinese itch, but you’ll instead be in a vibrant democracy that doesn’t require a special visa if you’re an American passport holder. Dating scene was very good to me and if you’re contemplating heading to the Philippines anyways, you’ll meet tons of Filipinas on dating apps in Taiwan. It’s where I met my Filipina wife a few years ago.