"The World's Easiest Problem Solving Class: Problem Solving Kids" Kensuke Watanabe Price: ¥1200 "The World's Easiest Right-Brain Problem Solving Class" Kensuke Watanabe Price: ¥1200 This is a set of two books. With obi (book band) No folds or writing #KensukeWatanabe #Kensuke_Watanabe #Books #Society/Education_and_Learning