This episode is unique because it also features a notable bonus segment involving a "Kappa" of the lake. The Yorozuya crew encounters an Amanto that resembles a mythical kappa, leading to several fourth-wall-breaking gints about legend-making and strange fish.
Gintama Episode 21, titled is a classic comedy episode that revolves around a heatwave in Edo and a desperate quest for an electric fan. Episode Summary
The Yorozuya office is unbearable due to a massive heatwave. After Gintoki and Kagura fight over their only electric fan and break it, Gintoki heads out to buy a replacement.