From puzzle master Nobuyuki Yoshigahara: "The World Puzzle Designers' Forum, held in August 2000 in Los Angeles, was where I first met my close friend Oskar. This brain teaser is based on a disc based puzzle that he showed me at that time. Battling it out with this puzzle is like putting your mind to the test against one of the world's sharpest minds in Oskar. The idea to keep in mind here is 'circle.'" Hanayama cast metal brain teasers have 6 levels of difficulty and each puzzle is Mensa-rated. Level 2 puzzles are considered fairly easy by most puzzlers.
