http://www.animenewsnetwork.com/news/2009-09-19/male-remains-fou nd-in-gunma-prefecture-mountains
Male remains have been discovered on Saturday morning in the mountains of Gunma Prefecture, the same general area where <cite class="e anime">Crayon Shin-chan</cite> creator <cite class="e person">Yoshito Usui</cite> was reportedly going hiking on September 11 when he went missing. Authorities have not identified the remains yet, but they told the <cite class="e company">TBS</cite><span> television station that the clothing on the remains resemble those of Usui. </span>
<span>According to Usui's family, he said he was "going hiking for a day in Gunma Prefecture" on the morning of September 11. His mobile phone was last </span>detected in the vicinity of Karuizawa, a town about 100 kilometers (about 60 miles) northwest of his Kasukabe home, on Monday. Karuizawa is located in the mountainous eastern part of Nagano Prefecture, near the border of the equally mountainous Gunma Prefecture. In particular, Usui is said to have expressed his intent to climb the Arafune mountain, which towers 1,422 meters (4,665 feet) high at the border between Nagano and Gunma Prefectures. Authorities have been searching this area since September 12.
At 11:00 a.m. on Saturday, the authorities received a report from climbers that "there are remains below a rocky ledge."
Source: TBS News
Update: More background information added.
If it's him, then wow... That's sad (well, it'd be sad regardless). I kinda liked Shin-Chan, even though I haven't seen it in a while.