There’re two laws regarding the use of cellphones and electronics in Japan which you need to be aware of as a foreign traveler to Japan.
The first one is the requirement for obtaining the local cellphone service (whether it is a prepaid contract or a postpaid one), or even a local telephone SIM, in Japan.
Since April 1st, 2006, the cellphone-related law called “the Act for Identification, etc. by Mobile Voice Communications Carriers of Their Subscribers, etc. and for Prevention of Improper Use of Mobile Voice Communications Services”, or in short, “Mobile Phone Improper Use Prevention Act (携帯電話不正利用防止法）” requires anyone who intends to have a voice-call-capable cellphone service (whether it is a prepaid contract or a postpaid one) to show a proper identification which indicates that s/he has the residential (permanent) address in Japan. A hotel address is not sufficient for this purpose.
This law became necessary because Japanese authorities, and especially the law makers, consider the fraud using the cellphones became a social problem, and the police and other law enforcement agencies want the address of all the phone owners to be registered so that, if any crime is committed using a cellphone, they can find the owner
Continue reading Two Laws regarding cellphone in Japan : No.1 “Buying” a local SIM