My wife and I went to Kitakyushu for the weekend. The hotel is very conveniently located about 10 minute walk from the airport. There is also a shuttle bus that runs back and forth between the hotel and airport. They offer free, quality, Japanese-style breakfast to the hotel guests as well as Curry and rice for dinner. The room wasn't that spacious, as typical of inns in Japan. But it had all the necessary amenities, including additional toiletries and bath robes for pick up at the front desk. The hotel staff had limited foreign language capacity despite the number of foreign guests from Korea and China, but they were all super friendly.
The inn is isolated from the city but you can take an airport shuttle bus (30-40 min ride) into the city center.
Overall, an excellent and comfortable experience.