Don't Complain About Your Job At Home, Do It Somewhere Else (S01E75)

Despite the danger of being canceled, Gintama has reached its second year. Gintoki claims that they were able to overcome it through manipulation, but Shinpachi reveals that they were almost canceled because of that. The Odd Jobs keep talking on and on and discover something terrible. They used up half a year's worth of their production money on the episodes up to now! They decide to look back on the past 75 episodes, but for some reason, the theme song is Otsu's “Your Mother is a XX.” Thinking it a bad idea to change the theme song, they put out a Prince Hata version of the opening sequence. (Crunchyroll)