A surreal satire from one of the founding fathers of contemporary Japanese letters, about a journey through an underground world inhabited by mythical, turtle-like creatures whose customs shed a disturbing light on human society.

In early 20th-century Japan, a lone hiker falls through a hole in the ground into Kappaland. This is a place ruled by amphibious creatures who share characteristics with tigers and turtles, but who, for all their strangeness, shed light on the human condition. In Kappaland children choose whether or not to be born, intellectuals think nothing of drinking themselves to death as part of a cultural demonstration, unemployed workers are saved the bother of supporting themselves by being turned into sandwich meat, and artistic rebels from the human realm are enshrined in the Great Tabernacle as saints. Gruesome as life is there in some ways, the Kappas are refreshingly honest about their practices, and it's a return to the world above that drives the narrator insane and sends him to the mental asylum.

This novel, the last work by icon of Japanese letters Ryunosuke Akutagawa, is a darkly comic and surreal satire, which challenges all the conventions of so-called polite society.