if the specified taxpayer is an individual: the following persons:

イa spouse or other relative of full age who shares living expenses with the specified taxpayer;

ロa person who has a close relationship with the specified taxpayer, by virtue of a contract with the specified taxpayer, with regard to the facts that are to form the basis for calculating the tax basis, etc. or tax amount, etc. of the national tax of the specified taxpayer;

ハa business operator that provides a venue on which the specified taxpayer continuously or repeatedly conducts transactions carried out using an electronic data processing system or other transactions;