At first glance it seems to be a typical lunch break at a local Japanese school: Boys rambunctiously chasing one another and yanking at each other's white polo shirts, little girls twirling so hard in their pleated gray skirts that they fall down with squeals of glee.

But look closer and you notice that although the signs on the wall are familiar, the Chinese characters are written in simplified form, unlike Japanese "kanji." A group of lanky adolescent boys in navy blazers start kicking around a fuchsia-feathered shuttlecock, or "jianzi," instead of a soccer ball.

"Ne ne, ore ne, hao chi de bing gan aru yo ne!" a little boy shouts, holding some biscuits up like a prize as he switches fluidly back and forth between Mandarin and Japanese.