Episode 21 is Two Part Episode
The Yorozuya help a kappa-like Amanto defend his lake from developers who want to get rid of it.
The Yorozuya are fishing in a lake only to find that most of Edo's ecosystem has greatly changed since the Amanto's arrival. Kagura catches a kappa-like Amanto with her fishing rod and Gin kicks it away being scared from his kappa appearance. The Amanto returns to the shore and grabs Shinpachi's leg demanding them to pay for breaking his glasses. He also gets hold of Kagura and Gin in the process. He asks them to apologize and wants to know why they tried to run away. Shinpachi apologizes to him and he rewards with him with a wet biscuit. Ready to get back in the lake, the Amanto tells them it's ok since the dish he has on his head is intact and introduces himself as Ebina. At that moment a gold club is thrown and breaks the dish on top of his head, which makes the Amanto act very shy. The club was "accidentally" thrown by the owner of the area, who is frequently threatening Ebina to get away from the lake, as he wants to fill it with dirt to turn it in a huge golf course. Ebina refuses to leave the lake and ignores the threats. He later explains to the Yorozuya the reason he came to Edo and why he likes this particular lake so much. His species need a lot of water to survive so he came all the way to Edo after crashing his spaceship. He had troubles however with humans as they saw him as a monster. One day a young girl, who had an incurable disease, tuberculosis, came at the lake and wasn't scared at all from Ebina. They were frequently discussing and enjoying each other's company. The girl was jealous of Ebina's ability to swim, while she couldn't because of her disease. Ebina made a promise with her to keep the lake safe until she got better and she could swim. A lot of years have passed since then and the girl has probably passed away, but Ebina doesn't seem to care and continues to guard the lake. Later at the same night the Yorozuya are dressed as Kappas and scare off the owner of the area along with the workers who tried to fill the lake with dirt. The next day Gin is fishing at the lake again and informs Ebina that the man has sold off the area and that the lake will be safe for some time. Ebina asks in shock if Gin was responsible for this, but Gin notices a small fish swimming at the lake avoiding responding to Ebina's statement.
- Kappas are mythical water creatures according to the Japanese culture that drown people and are fond of cucumbers.
The Yorozuya's fan breaks in the middle of a heat wave and Gintoki gets involved in a bizarre plot while trying to get a new one.