Since moving to Kurume, on the island of Kyushu in Japan, I've struggled to keep up the same level of outdoors activities that I was accustomed to in Sydney. This page details some of the info that might help people out of the same rut I was in.
I frequently ride on Kora-san and beyond, to the East of Kurume. There are a few tracks around, from above the shrine, at the top of the first peak, head onto the walking tracks to the south of the road and explore!
I also travel long distance by bike, recently a 10-day tour to Shikoku over Golden Week. Since then, I have also been involved in BEE Japan, and was a member of the 2004 team. The team spent 2 months cycling the length of Japan, I only had time to spend 3 weeks out with them.
I sometimes get out rock climbing. There are some nice areas around, many of the sport crags have an abundance of difficult climbs, not so many easier or intermediate climbs.
There is some nice multi-pitch climing in Miyazaki Prefecture.
The crags in Japan are, however, maintained to death, with the number of bolts sometimes resembling a metal coating on the cliff.
I haven't done much hiking since I arrived in Kyushu, but might start doing some more soon. It is one of the easier activities to find friends to join you, and there are some fantastic spots, eg Okue-san in Northern Miyazaki. Try for lesser-used tracks, to avoid being trampled by tour groups numbering up to 40 or so!