The Japan Amateur Baseball Association (JABA) announced the dates for all their tournaments next year. Below are three of their more important tournaments. You can view the rest of the list (in Japanese) here.
2012 Inter-City Baseball Tournament - between 7/13 and 7/24 at Tokyo Dome
All Japan Club Team Tournament - between 9/7 and 9/10 at Seibu Dome
Industrial League Championships - between 11/3 and 11/13 at Kyocera Dome
The JABA also announced that of the 14 teams from the Tohoku region that took the year off because of the March 11 earthquake/tsunami, 11 plan to resume operations and three teams from Iwate, Miyagi, and Fukushima will likely be disbanded.