Please check the domain's registrant and public contact information. If the domain is using GMO's postal address for its registrant, public contact or both contacts, that was the cause of the transfer failure.
As it is stated in our management panel, our proxy service is available only while a domain is managed under GMO JP-DRS service. It is necessary for you to change the domain's registrant address to a different Japanese address before you let it transfer out. Please make sure to change the postal code too, since all transfer requests will automatically be disapporved by our system if the domains have the postal code [150-8512] in the registrant and public contact information.