GlobalComix allows you to monetize your comic with paywalls, donation pools, etc. Though it won't do you any good to have your comic free to read on all platforms except for one, it's still something to consider if you ever want to take on a comic project that you want to try and monetize (especially considering all the monetization tools are open to everyone to try without any additional legal strings or contractual obligations attached).
Oh, also, you get to keep 65% of what you make, so the website split is great too
In terms of hosting on Japanese sites, you'd be hard-pressed to find a place that will let you self-publish without a publishing deal with the website and without having your comic translated to, yknow, Japanese. And considering the difference in culture, language, etc. I don't think it would really put you ahead of the curve to try and host with Japanese platforms.