Lumbus does not provide a truly unlimited data eSIM for Japan. The plans titled “Japan Unlimited” supply only 3 GB of high‑speed data each day and reduce speed to 1000 kbps once the daily allowance is reached. Because the data is capped, these plans are not unlimited; after the 3‑GB limit is used the connection speed is throttled.
Travelers who need more data can choose from Lumbus’s fixed data plans instead. For example, the Japan 50GB 30‑day plan gives 50 GB of high‑speed data for a month, and the Japan 20GB 30‑day plan offers 20 GB for the same period. These fixed‑data options provide larger data allowances without the throttling that accompanies the “Japan Unlimited” plans.