This has been one of my best experiences in Japan. This is a only-male capsule hotel. The staff was very friendly and they provided me a locker since I checked-in early. The hotel is very located, it is close to canal city, and you can veto to Hakata and Tenjin station by a 10 min bus trip or even by foot. The capsules are enough for one person (I am 1.8 m tall and I could fit inside) and you have a small TV and radio with a personal headphone to avoid disturbing your "neighbors". Bathroom, showers and small onsen (or ofuro) are public. You can find in every floor complementary tea, water and coffee service. There is also one restaurant at the ground floor but you can try Japanese food (Fukuoka'a ramen is vey famous) close to canal city or besides the river.
One thing that I really like about Japanese hotels is that they provide you toothpaste, toothbrush, comb, razor and this hotel is not the exception. If you don't mind to have no privacy then this would be the place for you. I traveled with my male friends and this hotel was part of our experience in Fukuoka.