Very hard, if u have no Nippon Blood 大和民族血脉. At very best, if u have Nippon name and Nippon with, u are considered 2nd class in their society - still better than Sinki who is considered 2nd class as Hardlander in own kampong
Even your presumed Half blood children, are only consider as Halfing Japanese…. Very hard to rise in their social status in Japan even your family is well-to-do