From snippets I've read over the years, SPN has long been popular in Japan. I remember back in S2 it was voted the then huge Prison Break as the most popular foreign show on Japanese TV, and SPN and J2 doujinshi are huge and now there's the Supernatural Anime project by the Madhouse studio in concert with Warner Brothers Japan.
The following is a 12 minute feature from the "King's Brunch" show on TBS in Japan. And before you mock it too hard have a look at any live morning TV show in your city! The interviewers suit is a quite unique thing of beauty.
The video has includes a recap of five seasons of Supernatural and damn but our show looks kick-ass! The voice casting is quite superb, the actors who do Sam and Dean (Yuya Uchida and Hiroki Touchi) especially.
There's also a short interview with Jared and Jensen - with tiny umberellas. I think there may be more to come as I know some fans were interviewed by the TV crew at VanCon.
more here on the interview with some more pics. Many thanks to tiptoe39 for providing a translation here