Is the "walk" part above figurative or literal? If literal then look no further than the 100 temple walk/hike around Shikoku. Figurative then look no further than Kyushu. I recently spotted a bus pass for "Q Shoe" called the Sun Q pass:

http://www.rakubus.jp/service/images...i/sunq_eng.pdf

Seem very popular with Chinese and Korean tourists.....

You could also get a JR Q Shoe pass:
http://www.jrkyushu.co.jp/english/kyushu_railpass.html

Places to see:Fukuoka:
Fukuoka City/ Dazaifu Tenmangu& Kyushu National Museum/Yanagawa/Mojiko Retro town and the Fish Market in Shimonseki across the straight/Hawks Baseball game (if that's your thing).

Kumamoto: Yamaga for local onsen experience/ Kikuchi gorge/ Mt. Aso/ Kumamoto Castle/ Kurokawa Spa/ Minami Oguni.

Saga: Yoshinogari/ Ureshino/Karatsu/ Imari-Arita for porceline and beef/ Yobuko for squid.

Nagasaki: Mt. Unzen& Shimabara peninsula/Unzen park/ Nagasaki City/Bomb museum and peace park/China town/Grover Garden/Huis Ten Bosch theme park/Sasebo for it's American influence.

Kagoshima: Kagoshima city/Sakurajima(Japan's most volatile volcanoe)/Imo Shochu/Kirishima area lots of spas and natural food.

Miyazaki: Nice beaches/Takachiho.

Oita: Yufuin/Kuju area for spas and beautiful countryside.......Just on the other side of Mt.Aso. Great drive from Beppu via Yufuin to Aso on the Yamanami Highway. Best train trips from Beppu to Kumamoto(across the top of Kyushu), Beppu to Hakata(via Kurume/Hita).
Kuju area for natural food. Beppu one of the oldest resorts on the island(seen better days IMO) but the tourists seem to enjoy it.