Ferry

Ferries can be used as cheap alternatives for long-distance travel.  You can leave Friday evening after work and be in Osaka at 8:30 am on Saturday morning, well-rested, bathed and fed!  A great way to spend a weekend in Kansai and you only need the Shinkansen to get back to Kyushu.

You can read more about domestice long-distance ferry routes:

http://www.japan-guide.com/e/e2355_01.html

For overnight service from Kokura/Shin-Moji to Osaka… From Kokura Eki Kita, there are two ferry lines that offer bus service taking you right to the port:

http://www.cityline.co.jp/english/index.html

http://www.han9f.co.jp/en/index.html

JR operates a ferry which connects Fukuoka and Pusan, Korea:

http://www.jrbeetle.co.jp/english/index.html

Kanpu Ferry goes to Pusan from Shimonoseki:

http://www.kampuferry.co.jp/

Wakamatsu–Tobata. This ferry is an alternative to the bus over the harbor between these two parts of Kitakyushu:

Tel 093-861-0961