Nurikabe

[1] Japanese scholar and folklorist Kunio Yanagita recorded perhaps the most prominent early example of nurikabe and other yōkai in his books.

With the exception of Mizuki Shigeru's experience in New Guinea, most legends and accounts of nurikabe come from Kyūshū, in the Ōita and Fukuoka prefectures.

[2][3] It has been suggested that the legend of the nurikabe was created to explain travelers losing their bearings on long journeys.

Mizuki attributes much of his inspiration for the series to an experience he had with a nurikabe in New Guinea[5] during World War II, as well as to the writings of Kunio Yanagita.

[2][6] Mizuki's illustration for the nurikabe gave it a more physical and anthropomorphic form with arms and legs, rather than the more traditional invisible wall concept.