This paper describes the invention of a sumo mat to secure safety for schoolchildren doing sumo in physical education classes. The first advantage of the sumo mat that we invented is that safety is secured by the difference of height of the mat. The second advantage of the mat is that it can be laid down easily and quickly anywhere, e.g. in a gymnasium, auditorium, classroom, or budo hall. The authors believe that the invention of a sumo mat will provide beginners—even small children—with a safe environment in which to practice sumo.
