Rakuten has recently released it’s mobile plan in Japan.
Amount of data you can use is relatively low however it contains global data roaming.
It is pretty good if you travel abroad frequently.
Also more Rakuten points can be redeemed by linking to your Rakuten Account as you shop online at Rakuten.
However there is pitfall for Docomo or Softbank based SIM user.
Currently, in 2020, data connection is done through 4G, but phone and SMS is done through 3G.
Despite you are in the range of Rakuten’s Frequency coverage area, you may have an issue phoning or texting.
This is because Docomo and Softbank uses GSM while AU-Kddi (which supplies 3G part of Rakuten Mobile) uses CDMA.
Before making contract, you want to ensure you’re smartphone is capable of handling CDMA so 3G connection can be established.