The package I got from Haikasoru contained three books, all science fiction. I've read two of them now, but already there's a great deal of range here. Anyone who wanted to point at Japanese science fiction and say, "Japanese science fiction is _____," would have as much trouble filling in the blank with one single thing as they would for Anglophone science fiction. Just on the strength of two books. I suspected as much, but it's good to have it confirmed.
This one is hard SF short pieces all in the same universe/future. There's a wee black hole called Kali being used to power all sorts of projects, and the company around that is the AADD, the Artificial Accretion Disk Development association. The stories range all over the solar system, with implications beyond, but they've got that same basic premise and some consistent concerns, the nature of intelligence and the nature of learning/education being big ones. If you've liked Greg Egan, this might well be the thing; if you really wish you liked Greg Egan but find him a bit abstruse, Hayashi is less so.
I haven't read the original Japanese, so in that sense I can't speak to how good Jim Hubbert's translation was, but one of the perils of translation is having everything come out sort of bland, as though the process of translation pulls the personality out of the prose, and there I can say Hubbert did a good job. The different sections have successfully different prose voices--Hayashi clearly has more than one mode of expressing a character's voice, and that comes through in Hubbert's translation, all to the good.
The one bit I struggled with was that in the first section they were investigating the murder of an accretion disk scientist. And his name was Graham Chapman. Some of you are now saying, "Yes, all right, do go on with what the problem is," and the rest are snickering in your sleeves. Because Graham Chapman was one of the Monty Python guys. So every time he came up, I was picturing, well, Graham Chapman. I kept saying things like, "How do you know he's an accretion disk scientist?" "He hasn't got shit all over him." And highly mature, relevant things like that, which were totally not Mr. Hayashi's fault, I'm absolutely sure that I will do something equally silly to a Japanese audience at some point with a Japanese character name. Still, I was glad that it didn't go on that way for the entire book.
("If you were the translator, would you have tried to change the name of that character?" timprov asked. "Yes, I think I would," I said. "Yah, something else similar in feel, but without the Monty Python reference," he said, nodding wisely. "Like Peter O'Toole.")