I'm pretty sure I visited that ninja attraction when I was in Japan back in 1992. It wasn't very built up back then, and consisted of a small village area, some shops, and the ninja house. The house was pretty cool, and for the technology of the time, I could see it befuddling anyone trying to "invade" a ninja's personal space...

When I lived in Japan from 1999 - 2002 I'd intended to visit the new and improved ninja park, but never got around to it...