According to his own conscience.
Which was against his country’s norms at the time.
A Man for All Seasons.
“You want to know about my motivation, don’t you? Well. It is the kind of sentiments anyone would have when he actually sees refugees face to face, begging with tears in their eyes. He just cannot help but sympathize with them. Among the refugees were the elderly and women. They were so desperate that they went so far as to kiss my shoes, Yes, I actually witnessed such scenes with my own eyes. Also, I felt at that time, that the Japanese government did not have any uniform opinion in Tokyo. Some Japanese military leaders were just scared because of the pressure from the Nazis; while other officials in the Home Ministry were simply ambivalent.
People in Tokyo were not united. I felt it silly to deal with them. So, I made up my mind not to wait for their reply. I knew that somebody would surely complain about me in the future. But, I myself thought this would be the right thing to do. There is nothing wrong in saving many people’s lives….The spirit of humanity, philanthropy…neighborly friendship…with this spirit, I ventured to do what I did, confronting this most difficult situation—and because of this reason, I went ahead with redoubled courage.”
Yes, There is the banality of evil.
And, Yes, he probably did pay for his life-saving kindness. He had a tough life, but the approximately 20,000 descendents of the individuals who he helped are glad that he did the right thing, in his own mind.
Others could not, and more importantly, did not do the same. But, it was a natural thing, FOR HIM. It’s called personality: Character AND Temperament, two sides of the same coin. You cannot separate them. It is a whole.