Naruto is shows on TV Tokyo but produced by Studio Pierrot. The Japanese website is here. As for getting imported DVDs, I would run a search on Yahoo Shopping or check out RightStuf. It's been almost a month now since I've been in Japan, but I don't recall seeing any Naruto box sets, although there are certainly enough DVDs out for them to have been put together.

Just remember, though, the Naruto DVDs (at least the early ones) don't have English subtitles. If I remember right you can speak some Japanese, but only you know whether or not you're good enough to follow along....