There is a question I find confusing on Visit Japan Web (VJW). I believe each adult family member needs to have an individual VJW account (while babies and infants are added to the adult's VJW account).
Under Customs Declaration section on VJW when it comes to the 'number of family members traveling with you', are we supposed to put '0', if all family members are adults and each family member has their own individual VJW account?
I would assume you'd put the full number of people that you're on the journey with. Otherwise it would say no. Of dependants (again, assumption here). Enjoy Japan.