Who is The Assistant Magistrate from The Master Puppeteer and what is their importance?

The assistant magistrate comes into the story when Saburo posts a notice demanding a special showing of The Thief of the Tokaido for the poor. He tells Yoshida that the performance is forbidden. Yoshida manages to play him perfectly, putting on an act of subservience and pointing out that the performance would be a great opportunity to catch Saburo. He comes back the next day and tells Yoshida that the performance must go ahead after all. At the end of the play, he and all his men are robbed by the bandit.