In the early 1750's, the Tosa government put a monopoly system in place to enable paper merchants to pay low prices for paper from local producers. The merchants would, in turn, sell paper to Osaka for a large profit, which would benefit the financially struggling administrators of Tosa. However the low prices paper producers were forced to sell at caused these producers much hardship. When a petition put forth by Tsunoyama complaining of low prices being paid to producers was ignored, Nakahira Zennoshin led a protest against the unfair practice. He was jailed, and continued to protest for 2 years until his execution.
On the day of his execution, a typhoon struck Tosa province, and would be remembered for years for its destructive power. Many felt that the typhoon was a punishment by the gods for the greed of the Tosa government.