There is no way.

First, there is no transfer service for telephone numbers in Japan. Even if the original owner of the number terminates the contract and does not use the number, the number will remain vacant for more than one year. In order to reduce the rate of accidental calls by the original owner's friends as much as possible .

Secondly, even if the number has been out of use for a long time, you will not be able to select the number because you can only select 4 digits and cannot select all 11 digits.

Third, the need for parental consent refers to the situation where the phone user is a minor, and the authorized signature of the parent (guardian) is required before the phone can be installed.

For reference only