I departed from Busan as a solo traveller - check-in was very quick and easy; travelled back with my boyfriend and it was similarly easy from Japan. Note that the price via aferry is better than you can get locally here in Busan! Ferry service itself is fine (though usually at least one ferry toilet seems to be out of action!). (I have no idea about onboard catering, but was required to include a rating for it, btw.) Customs in Fukuoka is not always fun; as the ferry route is comparatively rarely used by 'westerners' they seem to pick on them which is annoying (i.e. allow time to have your suitcase gone through for apparently no reason). Otherwise a very good, speedy route - and much cheaper and more eco-friendly than flying. Fukuoka/Hakata is easy to navigate; buses from just outside terminal into town - and of course great train connections from there to the rest of Japan!

The ship is fairly basic, but this is made up for by the fact that the views to be seen en route are simply breathtaking.

The on board staff were helpful when called upon and the seats looked comfortable, but I decided to spend my time out on deck!