There are many seaside cliffs in Aomori prefecture, many you will notice are littered with rusty old lost arrows and other make shift pitons. It is a daunting task finding English information in Aomori so if you find a Japanese climber that speaks English, treat her/him as a king. The bouldering possibilities are stout, and if you can deal with the cold, you could climb year round. Hachinohe has a wonderful resaraunt called BON. It is on a funky pedestrian ally and hard to find but worth it. The owner speaks english well and is a surfer, mountain biker, and traveller.
Express train from Tokyo, channel tunnel or ferry from Hokkaido.