GRASS MOBILE
Official dealer of DOCOMO, SOFTBANK, AU and UQ – providing cheap data SIMs, voice SIMs, portable WiFi and fixed WiFi for foreigners in Japan.
Buy International Travel eSIM/SIMStay Connected Across 5 Continents
Planning an overseas trip and unsure where to buy a travel SIM? Get international travel SIMs on MoMo, with high-speed 5G/4G data in 200+ countries worldwide.
- Buy international travel eSIM in just a few simple steps
- High-speed 4G/5G data, seamless browsing
- 24/7 support throughout your journey
HIGHLIGHTS
Quick activation & support
We help activate your service and quickly resolve issues during use.
Online management system
Customers, partners and dealers easily manage orders, products and plan details on the MY GRASS system.
Diverse products
SIMs, Pocket WiFi and Home WiFi – telecom solutions for every need.
Flexible payment
Convenient payment options including bank transfer, Yucho, SmartPIT and COD.
Set up. Assign. Deliver.
Stop wasting time on tools. Taskly gets you set up in minutes so your team can focus on work that actually matters.
Consult & choose a plan
Find the SIM/WiFi plan that fits your needs and budget.
Pay & receive
Pay online or by bank transfer and receive your SIM, device or eSIM QR code.
Activate & set up
Guided SIM/eSIM activation and APN setup to get you online. Voice SIMs require an eKYC procedure.
Care & companionship
Technical support and answers throughout your usage.
Consult & choose a plan
Find the SIM/WiFi plan that fits your needs and budget.
Pay & receive
Pay online or by bank transfer and receive your SIM, device or eSIM QR code.
Activate & set up
Guided SIM/eSIM activation and APN setup to get you online. Voice SIMs require an eKYC procedure.
Care & companionship
Technical support and answers throughout your usage.
PRODUCTS & PLANS
Find the best SIM & device for your needs
SIM DATA
High-speed data plans, 1GB–100GB or unlimited
VOICE SIM
Domestic voice SIM, free calls to all carriers
POCKET WIFI
Portable WiFi device, stable connection anywhere
HOME WIFI
Fixed home WiFi, high-speed & affordable
Standard-compliant eKYCMaximum Identity Security
Looking for fast, secure, and legally compliant identity verification? My GRASS integrates an international-grade eKYC system to verify customers in seconds while ensuring security and regulatory compliance.
- AI-powered automated identity verification with 99%+ accuracy
- Complies with ISO 27001 security standards and applicable laws
- End-to-end data encryption for absolute protection of user data
Your questions,Grass answers
Frequently asked questions about SIM and WiFi in Japan
Please review the following notes before using eSIM:
- Install eSim 6-12 hours before your flight.
- eSim can only be installed with an internet connection.
- Do not enable Data Roaming until you arrive at your destination.
- Do not delete eSim after activation – it can only be activated once.
- eSim cannot be transferred to another device after installation.
Need SIM & WiFi advice?
Contact GRASS Mobile to pick the best SIM, eSIM and WiFi plan — fast activation and dedicated support throughout.