Well, you can go to
http://babelfish.altavista.com and translate a whole page from Japanese to English if you wish. I just did, and although the translation isn't fully understandable, could have a quick look through their message board, where they discuss about time trial issues and the PRs they got.
Martin has already posted the ranking page's URL, though other interesting URLs are the site's main page:
http://www.geocities.co.jp/Playtown-Toys/7466/index.html, from which are linked off 7 SMK sub-pages; and their message board:
http://hidebbs.net/bbs/bakaya6777?sw=7, which I suggest you strongly to translate from Japanese to English, unless you can read Japanese.

From the quick look I had through some of the site's parts, including the message board, the records listed seem to me rather reliable. They know very well about the boosting technique, and how it allows to cut through 1st and 4th corner in MC1, and they know as well about the zigzag way to create a boost, which I
believe, is what they have used on the first straight of MC1 to cut through the following corner, helping them to get those ridiculously low MC1 times. But I might be wrong on that, I think I read also somewhere about MC1's 5th turn being involved, and I had a very quick read through the messages anyway.
Other than that, their RR records are also pretty good (1'25"55/16"97 for now), and it seems they are just getting started there, as many of their message board's messages were related to PR progress on RR. They also seperate trick times (water tricks in KB1 and VL2 and "hole tricks" in some of the GVs and RR) from "normally" gotten times, what we would call Non-SC times, though it is clear there is no boosting restriction, and they are in fact using them a lot on courses like MC1, MC2 and probably a few others.
To sum it up, it is clear they built up something really considerable as far as time trial competition goes, and I'm convinced it would be in the benifit of everyone if both of the communities could get to contact each other and work something out in cooperation, because they have some very skilled players, yet it feels like they are just getting started.
If at least some people could get involved here, that would be great. I would suggest you strongly to have a deeper look through their site's features and especially the message board with the assistance of an online translator, as we can probably learn a lot about them, there. I didn't really have a whole lot of time myself to check deeply most of their posts, as I'll be going to bed in a few minutes. (and especially since some of the sentences are really complicated to understand through automatic japanese-->english translation)
And lastly as soon as possible, we should contact them, more likely through e-mail. Mitsuya Mikan, who is currently on the SMK player's site, seems in fact to be the Japanese site's webmaster, and Sami had contacted him briefly to get his times onto the SMK player's site, so I believe we should be able to contact him again. I really hope personally that it will be taken seriously, because I would not like the SMK community to turn into what the MKSC community somewhat turned into, with Japanese players playing on their own, and different people updating the WR sheet from time to time with times taken from their site. Cooperation is in my opinion the best issue.