Akuei to Gacchinpo follows the surreal, gag‑packed adventures of Takeshi, a Japanese boy who, after experiencing severe toilet troubles, takes a bathroom break from class and is unexpectedly sucked down a toilet into an underwater world. There he encounters the spunky Jasmine, who drags him into her organization, UNCO, to fight the evil PIPS, a group bent on destroying the world. Together with Jasmine and their friend Akuei, the trio travels between the underwater realm and Springtown, Taiwan, tackling the PIPS while dealing with a series of wacky hijinks along the way.