For Japanese online shoppers (Rakuten/Amazon, etc.): Many Japanese e-commerce platforms, auction websites (such as Yahoo Auctions, Mercari), or ticketing websites require users to link a Japanese mobile phone number and receive two-factor authentication SMS messages during registration. For heavy users in the Japanese economic zone: A Japanese mobile phone number is needed to register for a Rakuten ID, Rakuten Card, or various points cards to seamlessly accumulate and use points when shopping on Rakuten Market. For international students/workers in Japan who need to maintain a Japanese mobile phone number: Switch to a low-cost plan with Rakuten Mobile before returning home. The number can be retained after returning home to receive verification codes from banks or government agencies, preventing the number from expiring and being cancelled.

Supports registration for various applications including WhatsApp, LINE, Telegram, Snapchat, and Instagram. Supports Apple iMessage and FaceTime, suitable for users who need efficient registration and communication.