MobileSIM eSIM Data Plans for Japan

MobileSIM does not provide a true unlimited eSIM for Japan. All plans that use the name “Unlimited” actually limit high‑speed data to 3GB per day, after which traffic is throttled to 1000 kbps. Because of that throttling, data is not truly unlimited. Travelers who need large amounts of high‑speed data without speed reductions can choose from MobileSIM’s fixed‑data plans, such as the 20 GB plan for 30 days priced at $25 USD or the 10 GB plan for 30 days priced at $18 USD. These plans give a larger, unreduced data allowance and may be more cost‑effective for heavy‑use travelers.

MobileSIM does not provide eSIM plans for Japan that include a phone number or SMS service. The provider only offers data‑only eSIM options in Japan, so travelers cannot use local voice or text services from the device.

To communicate while traveling, you can rely on internet‑based apps such as WhatsApp, Telegram, and iMessage. These apps work over the data connection and allow calls and messaging without needing a local phone number or SMS capability.

MobileSIM offers 12 single‑country (Japan‑only) plans and 22 multi‑country plans that include Japan. The plans are priced between $2.34 and $89 and provide data from 200 MB up to 100 GB over 3 to 180 days. Plans are split into daily data‑cap options, which limit the amount of data you can use each day, and fixed data‑cap options, which allocate a set amount of data for the entire validity period.