Yoshito Usui was reported missing on September 12th, 2009. A body whose clothes resembled his was found on September 19th, 2009.

On Sunday, September 20, 2009, authorities identified the body discovered at Arafune mountain as that of missing Crayon Shin-chan manga creator Yoshito Usui through dental records and other means. He was 51 years old.

The Crayon Shin-chan article in the English Wikipedia adds:

"Due to the death of author Usui, the manga in its current form ended on September 11, 2009, as announced in a broadcast of the anime on October 16, 2009. Although the series formally ended on February 5, 2010, it was announced on December 1, 2009 that a new manga would begin in the summer of 2010 by members of Usui's team."