One of my personal favorite event guides is the JR West and JR East sister-site combination "Odekake-Net" and "Eki-Net." Their starting pages aren't much to gloat about. Although Odekake-Net gives you a large friendly map of western Japan on its home page, this isn't what you actually want to be clicking on. And Eki-Net's layout is just another Yahoo! Japan style mess of thumbnails and text. For the real gold of these sites, follow the directions below:
That large map on the front page will give you some good info about famous locations to visit in Japan, but the far more impressive, constantly-updated list of events is more easily accessed from the pull-down menus at the bottom of the site. Under the button labeled イベント検索, pick the prefecture or region you're staying in or visiting, and you'll find a friendly and useful list of seasonal events going on around you. The list includes items like festivals, flower shows, and museum exhibits, along with their running times, entrance fees, and addresses of their locations. It's provided me with some nice day trip ideas, and you might find it useful for date ideas or planning family outings as well.
For you Eastern-Japaners, the event list is located along the right side of Eki-Net's starting page. It has a similar pull-down menu, labeled 祭り・イベントはこちら♪ and with a similar location selection set-up. Click on your prefecture and then hit "検索" to get the same type of event list as Odekake-Net offers: You'll be able to find out how long each event is running, how much it costs, and exactly where it is.
If you have any favorite event guides that you use in Japan, please let us know. We're always interested in expanding our horizons, too!