Most Japanese are not even religious. To them faith is something cultural. Whatever religion is part of their culture, it is usually pantheistic. Out of 124 million people, a few thousand Christians are an aberration. Christianity as a culture is alien to the Japanese.
As I said, Korea is much more receptive to Christianity -- without martyrdom.
Are you actually claiming that the Orthodox don't believe in the Gospel? That's an amazing statement coming from someone who claims to be defending the Orthodox Church.
Actually we do and are active in Asia, Africa and S.America. The difference is in the way you do it and in how you approach charity. There is no door to door stuff or street cornor screaming. Instead, the Church moves in and starts building soup kitchens and schools and orphanages and hospitals. The Word then spreads from there to those who want to learn.