What this exact variant is
| Device | Rakuten BIG s |
|---|---|
| Model number | Not specified |
| Original sales channel | Rakuten Mobile |
| Release date | 2021-04-21 |
| SIM / eSIM | eSIM |
| LTE bands | B1 / B3 / B4 / B5 / B7 / B12 / B17 / B18 / B19 / B26 / B38 / B41 / B42 |
| 5G bands | n77 / n257 |
| VoLTE / IMS | See the Japanese source record for the exact wording. |
| FeliCa | See the Japanese source record for the exact wording. |
This page evaluates the exact sales variant, not only the marketing name. A Japan carrier model, manufacturer SIM-free model and overseas model can differ in SIM layout, supported radio bands, FeliCa and carrier provisioning behavior.
Compatibility across Japan's four major carriers
| Target network | SolQvia rating | Basis | Important boundary |
|---|---|---|---|
| NTT Docomo | Partial / limited | Technical fit assessment | Verify plan, VoLTE/IMS and carrier support separately. |
| au | Partial / limited | Technical fit assessment | Verify plan, VoLTE/IMS and carrier support separately. |
| SoftBank | Partial / limited | Technical fit assessment | Verify plan, VoLTE/IMS and carrier support separately. |
| Rakuten Mobile | Strongest fit | Technical fit assessment | Verify plan, VoLTE/IMS and carrier support separately. |
Rating meaning: “Strongest fit” generally indicates the original selling carrier or direct primary-source support. “Major-band fit” means key radio bands are present, but it does not prove VoLTE/IMS, SMS, emergency calling, carrier aggregation, 5G SA or support eligibility.
Safe order when moving this phone to another carrier
- Confirm the model number. Check Settings/About or the regulatory label. Do not rely on the product name alone.
- Confirm the SIM path. Verify physical SIM versus eSIM support before ordering or reissuing a line.
- Check the target carrier's key LTE bands. Missing a low-band coverage layer can affect indoor and rural usability even if service connects in some locations.
- Provision the line. For eSIM, add and enable the carrier-issued profile first. APN values are not eSIM activation credentials.
- Check data, voice and SMS separately. Data working does not prove VoLTE/IMS voice support.
- Check 5G last. Verify n77/n78/n79, plan eligibility, coverage and NSA/SA conditions after LTE is stable.
Japan vs overseas model boundary
Sales-history inclusion prioritized。release date should be re-checked on the individual product page。
When importing or reusing an overseas model in Japan, also verify the exact regional model, Japan regulatory compliance/technical conformity, emergency-call behavior and carrier support. Do not infer these from a visually identical model sold in another market.
Primary and official sources
- network.mobile.rakuten.co.jp
- network.mobile.rakuten.co.jp
- network.mobile.rakuten.co.jp
- www.docomo.ne.jp
- www.au.com
- www.softbank.jp
- schema.org
- solqvia.com
- solqvia.com
- solqvia.com
- solqvia.com
- www.docomo.ne.jp
- www.docomo.ne.jp
- www.au.com
- www.softbank.jp
- network.mobile.rakuten.co.jp
- solqvia.com
- solqvia.com
- solqvia.com
- network.mobile.rakuten.co.jp
Carrier procedures and product specifications can change. Re-check the current official page immediately before a SIM/eSIM migration, MNP request, purchase or imported-device use.