Contest style practices in paper crane making have been conducted for two purposes. The first one is for the improvement of interest and motivation in learning about the fundamentals of mechanical engineering. The second one is for the understanding of the importance of natural science. Upon instruction, a hypothesis was framed:Successful experience by oneself deepens understanding and raises interest and motivation. It was found that many students gave themselves high selfevaluations even though their records were not successful. Furthermore, many students described in their reports that they learned much from failures or mistakes in their own work, as well as from works generated by others. The hypothesis was effective, but a revision is to include another point of view:Learning together in groups.