Kazuyo Matsumoto remembers all too clearly how her son's kindergarten sports day used to prey on her mind weeks before the event. She'd worry, not about whether her son would stumble in last, but about the "bare all" contest she would be forced to participate in at lunchtime. The judges were not the city hall officials standing under the shade of the marquee, but the mothers of her son's classmates.

"He had run his race, and now it was my turn to be judged," explains the 31-year-old waitress.

She'd open the Pokemon bento (lunch box) she had slaved over since 5:30 a.m. and slowly hand it to her son, guaranteeing all the surrounding mothers a good look at the elaborate contents. "I had told him to offer his food around because I wanted the other mothers to see I was taking care of my child," she says.