Updated: April 7, 2021
Pentax is now part of Ricoh. See their camera repair centers in Japan below. Besides an English list of their service centers in Japan, you can easily browse other lists of Pentax service centers in other countries.
See this Web page for Ricoh/PENTAX service centers in Japan (Tokyo and Osaka) in English:
http://www.ricoh-imaging.com/inquiry/asia.html
The Japanese list:
http://www.ricoh-imaging.co.jp/japan/support/repair_entry-j.html
