It's hard to put into words what makes this film so good (and I'd actually written a whole review on this before the stupid app crashed, so now I'm rewriting it), so I think I'll just stumble my way through a few vague paragraphs and call it a day.
His Motorbike, Her Island focuses on a carefree guy who drifts through life, and doesn't seem to care about much other than his motorbike and pretty young women. Early on, he dumps a very nice girlfriend, has to deal with her angry older brother, and ends up travelling around Japan, falling for a free-spirited girl who doesn't actually own an island, as the title might suggest, but instead lives on one.
The story might sound like much, but it doesn't need to be, because the main appeal of His Motorbike, Her Island is how it looks, sounds, and feels. It's a stylish and hypnotic movie, and feels unlike much else out there. Even if Nobuhiko Obayashi's best known film is the cult classic comedy/horror film Hausu, I think I liked this one more.
As long as you go in accepting this is more about style than emotion instead of plot or characters, I think it's easy to get a lot out of this. The fact that the pacing isn't always perfect and the final act loses its way a touch is easier to forgive when the whole film is such an interesting one to experience on an emotional level above all else. I'm also glad it didn't exceed 90 minutes - I think its unique pacing may have started to challenge me more if it had gone on much longer.