One morning in June, my kids left for school without their usual leather backpacks. Instead, they each carried a knapsack with a water bottle, a ground cloth and a handful of my sentakubasami. Clothespins? Yup. Standard equipment for the Zenko Shasei Taikai (All-School Sketch Festival).

Once a year, my children's entire school walks together to a verdant park at the edge of our school district to draw and paint for half a day. Like so many events at the Japanese elementary school my children attend, the shasei taikai is a bit of a mystery to me. We didn't do anything like this when I went to school in the United States. It seems odd to devote an entire morning to an art activity. And odder yet that the entire student body goes together. I decided I needed to go see what this event was about.

The park is one of the larger green spaces in central Tokyo, an urban oasis with wide-open play areas and a pond with ducks and turtles. Benches shaded by wisteria vines. There's even a waterfall I thought was real until I went through the park one evening when the pump had been turned off for the night. The park felt full once our 300 students settled in. Everywhere I turned there were kids in white school hats getting out watercolor sets.