Sonya Park opened her Tokyo-based brand Arts & Science in 2003 to stock, make, and sell the stuff she wanted, and what she wanted was old-school high quality inflected with some contemporary edge. Or something. It's a joushitsu na laifustailu emporium, I can tell you that.
Better to show an example, like the pajamas from A&S's first kid's collection, which have simple, traditional styling, but are made from very fine organic cotton. And when adjusted for 150 years of inflation, I'm sure the 29,400 yen price tag is very reason--oh, who are they fooling? These things are as expensive as The Last Emperor's longjohns.
Arts & Science - Something sleepy: 100% organic cotton pajamas, 80cm/100cm [arts-science.com via happy accident]
She couldn't find contemporary high-quality kids stuff in Japan? Was she only shopping on the kids' floor of department stores in Tokyo or what? :)