Ubigi

Being owned by NTT DOCOMO, one of Japan's largest carriers, gives Ubigi a real edge in a part of the world where network access can be tightly controlled and where being an approved MVNO partner matters more than in Europe or the Americas. That relationship shows up in dedicated, well-reviewed country plans for Japan, South Korea, and Thailand, markets where some independent resellers struggle to offer consistent speeds.

Alongside those single-country options, Ubigi runs a broader "Best Asia" regional plan for travelers hitting multiple countries on one trip, priced the same way as its other regional bundles: cheaper per gigabyte the more data you buy, generally landing between $2 and $4 per GB once you're past the smallest packages. The eSIM installs once and keeps working as you move between covered countries, without needing a fresh profile at each border. It's data-only, with no setup fee. It's a strong first choice for a Japan or Korea trip specifically, and a reasonable one for a broader Southeast Asia itinerary.