If you are Hong Kong residents and Taiwanese, you can use a free sim card until 500MB for 15 days in Japan.
You may use 2,500 times for web accesses,100,000 e-mails,236 minutes for YouTube movies,680 times for Google Maps and Skype for 930 minutes by 500MB.
WAmazing company starts free sim card business from February,2017.
They prepare vending machines at airports in Japan so when you come to Japan, you can get a free sim card.
Firstly, you should download their app in your smartphone and register for your details after that you can get a QR code and then when you come to Japan, you use this QR code for getting a free sim card.
WAmazing company can get fees from Japanese hotels. When customers spend money for hotels from thier app after that they can get commission fees from each hotels.