Choose the coverage map by your exact Sakura Mobile product. Sakura uses different networks across its SIM/eSIM range. A search for “Sakura Mobile coverage map” can lead you to a Docomo map even when the travel eSIM you are considering uses au by KDDI.

Source check: October 17, 2026. This is a guide to official product information and carrier maps, not a field test, speed test, or report of personal use. Network assignments and map interfaces can change; confirm your exact product before purchase.

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Which network and map should you use?

Match the complete plan name, including Travel or Monthly, Data-Only or Voice+Data, and the allowance. The following four rows cover only the named SIM/eSIM products; they do not describe Sakura Pocket WiFi or home internet.

Sakura product Network in the official FAQ Official map starting point
Travel 3GB/day Data-Only SIM/eSIM NTT Docomo Docomo areas
Travel Unlimited Data SIM/eSIM au by KDDI au area map
Travel 3GB/day Voice+Data eSIM au by KDDI au area map
Monthly SIM/eSIM plans NTT Docomo Docomo areas

The three Travel rows come from Sakura’s Travel SIM/eSIM comparison FAQ, whose October 10, 2026 update includes Voice+Data. The Monthly row comes from its separate Monthly SIM/eSIM coverage FAQ. Sakura’s travel eSIM product page also labels the Data-Only 3GB/day option Docomo and Unlimited option au.

“3GB/day” alone does not identify the network: the Travel Data-Only and Travel Voice+Data options use different carriers. An older two-column search excerpt can miss that distinction. Read the current FAQ and your order’s full product name rather than choosing a map from a search snippet.

Open the right official map

For a Docomo product, start with the English Communications/Areas page. It links to Japanese coverage information for 5G and 4G/LTE. The Japanese area page lets you choose a prefecture and continue to the service-area map. Use the map’s current legend and service selection; different colors or layers do not all mean the same thing.

For an au/KDDI product, use the English area information page or go to its service-area map. Check the legend before interpreting a shaded area, and distinguish current service from any planned expansion shown. A carrier’s map does not establish which network features are included in your Sakura plan.

Check the places your family will actually visit

Work through your itinerary rather than checking only the arrival city:

  1. Accommodation: locate the hotel’s actual address, including any countryside overnight stay. A city-center result tells you little about a separate rural property.
  2. Attractions: check the specific museum, park, trailhead, or meeting point. A destination name can cover a much larger area than the place you intend to visit.
  3. Travel between stops: follow the road or rail corridor, especially when leaving major cities. Coverage at both endpoints does not promise an uninterrupted connection between them.
  4. Independent outings: if family members split up, check each person’s destination and make sure they can access the meeting address offline.

Treat the map as an area guide, not a promise of indoor reception, continuous route coverage, or a particular speed. Open Notes on the au map for its reception limitations. Sakura’s Monthly coverage FAQ notes that congestion, weather, and the device can affect signal even in a covered area. We have not measured reception at your hotel or along your route. Save essential addresses and transport instructions offline before departure.

Check the phone separately

A colored map cannot confirm that your phone will work with the plan. Check the exact model and regional variant, carrier-unlock status, supported service, and eSIM compatibility against Sakura’s current requirements. Do this for every phone that needs its own connection.

Use our Japan eSIM checklist for compatibility and setup checks. For a broader provider decision, read the Mobal vs Sakura Mobile comparison. If you are still choosing between separate SIMs and a shared router, start with our family internet guide. Those decisions remain separate from selecting the correct coverage map.