All the kids got together into two mixed-age teams (not much choice in this tiny school though!) for a variety relay:
Balancing a ball between two posts
Big kids pulling a little kid on a tyre.
Ever tried a three-legged race? This is several steps up - six kids coordinating their steps. Actually this kind of race is a really big deal in Japan. They have prefectural champions then the best teams go on to the nationals. The teams are bigger, about twenty kids. They work really hard and there's usually a documentary on TV about one team or another and how hard they worked.
This is also a kind of varitey relay, 'unmei' or 'fate' relay. Instead of just running, they run to an envlope on the ground, placed randomly, and they have to open it and do what it says inside. Things like 'find two old men and run with them' or 'find a giant ball and run with it'. It means that it's just pure luck whether you win or not! This picture show two who got 'piggy-back a kid' as their fate.