Anime News Network has word that Japanese police are searching for Crayon Shin-chan creator Yoshito Usui, who has been missing since Friday.

The investigation began on Saturday in Usui's hometown of Kasukabe, Saitama Prefecture, and has expanded to other jurisdictions. According to reports, neither Usui's family nor his publisher Futabasha has had contact with the 51-year-old mangaka.

Debuting in 1990, the popular Crayon Shin-chan follows the adventures of a rude, crude and rambunctious 5-year-old boy in Kasukabe who's obsessed with bodily functions and older girls. The manga was adapted as an animated television series in 1992, and has spawned 17 anime films.

The manga is published in North America by DC Comics' CMX imprint.