I went to parts of Kyushu and western Honshu this weekend to enjoy the blossoming of the sakura. Enjoy.
Beppu has a number of places good for hanami, the most centralized being Beppu Park (別府公園) just north of the station. Kannawa has an excellent viewpoint as well.
The most accessible place in Kokura seems to be the River Walk shopping center, adjacent to Kokura-jo (castle).
My favorite place thus far. Iwakuni is always a vibrant place around the Kintaikyo bridge; toss some cherry blossoms into the mix and you get a pretty good crowd of locals, photographers, and foreigners. The path on the northern side is completely lined with sakura for at least three kilometers.
Irori Sanzoku Restaurant, Yamaguchi