Episode 35 OMG Part 2

"How did it come to this?" - This must have been the question the Christian missionaries asked themselves as Hideyoshi followed by successive Tokugawa Shoguns made life unbearable for Christians in Japan.  If only we had handed over the ship...if only we'd handed over the treasure.....if only we had that Englishman beheaded.....

It would be hard to find a group of Japanese more oppressed than the Christians.  But why were they especially targeted?   What threat did they represent?