S1·E43 The Shogun's Secret Ninja

Female ninja Osono's dad Seiemon comes to town. He is now a cotton-farming country samurai. Needs dried sardines for fertilizer. The hatamoto of sardineland is driving the fishermens' prices down so all the farmers secretly sell to Seiemon. The merchant tries to assassinate Seiemon and fails, since Seiemon is a ninja. Seiemon stays at the firehouse and plans to secretly assassinate the criminals, then kill himself, because he's depressed.