As usually happens with hereditary rulers, the Tokugawa family did not always produce competent men for the top job. Sometimes these men were so weak or distracted that they were practically prisoners of their advisors, which tended to encourage corruption. Corruption, of course, does not help a worsening financial situation. The Bakufu and daimyo several times canceled their debts to merchants and sometimes restructured them - for example giving themselves 200 years to pay back a loan with no interest charges. The merchants were powerless to do anything about this. Of course, as North Korea proves every day, a bankrupt country can survive if there are no other catalysts to light the revolutionary fires. Fortunately, in Japan there were two major catalysts for change. First was the internal factor: the rise of the National Learning school caused men to question their loyalty to the shogun. After all, wasnt the Emperor the proper focus of loyalty? The shogun was merely the Emperors servant, supposedly working on the Emperors behalf. As you can see, this is not immediately fatal for the Tokugawa. They were still the most powerful daimyo and the appointed servants of the Emperor. Had it not been for the return of the Europeans, the Bakufu could have survived National Learning, at least for several more years. It even had the strength to survive the civil disturbances and peasant revolts. But the Europeans came back and this time they had science on their side. They were the second factor.