SHARK Hanayama Cast Metal Brain Teaser Puzzle (Level 1) Hanayama's Shark Puzzle is a high quality cast metal brain teaser from inventor Akio Yamamoto Discover how to separate these two interlocking pieces and then try to reassemble them! Hanayama cast metal brain teasers have 6 levels of difficulty and each puzzle is Mensa-rated Level 1 puzzles are considered easy by most puzzlers