ByteSIM eSIM Data Plans for Japan

Yes, ByteSIM sells unlimited‑data eSIM plans for Japan. The available options are the “Japan – 5G Ultra Unlimited eSIM by KDDI” series, which come in several validity periods ranging from 4 days to 31 days. Prices start at $18.90 USD for the 4‑day plan and go up to $79.90 USD for the 31‑day plan.

These plans are advertised as unlimited, but the provider applies a Fair Usage Policy: speeds may be throttled after heavy usage, usually limiting the data rate to about 10 240 kbps. Users concerned about potential speed restrictions should contact ByteSIM directly to confirm whether a throttle applies and to determine how much data remains available at normal speed.

ByteSIM does not provide an eSIM plan that includes a local phone number or SMS capability for Japan. All ByteSIM eSIMs sold for Japan are data‑only plans, so travelers cannot receive or send text messages or make phone calls directly through a traditional phone number.

Those who need messaging or calling services can use internet‑based applications such as WhatsApp, Telegram, or iMessage over the data connection. The availability of VoIP services can vary in Japan, so it is advisable to verify that the specific apps you rely on are accessible in Japan before purchasing a ByteSIM data plan.

ByteSIM currently offers 94 single coverage data plans specifically for Japan. These plans range in price from approximately $2.90 to $89.90 and offer data allowances from 500MB up to unlimited data. Of these, 49 plans feature a daily data cap, while the remaining 45 provide a fixed data amount. ByteSIM does not currently list any multi-country plans that include coverage in Japan.