抄録
A constuction toy like Lego has been considered as a good creative toy because of its flexibility. Though, competition in the toy market has led to more new components and realistic models. This change seems to have made a radical contradiction to the original requirement of a construction toy : "children can build what they want by themselves". In this article, I studied the requirements of a flexible construction toy with realism. Thus, I would not propose to go back to the "ideal, genuine construction toy". What we need indeed is not only new well-designed parts but, motivating children to be autonomus to design, study, and build by themselves.