Don't get me wrong. The little Danish building blocks have plenty of inner beauty, sure, and are one of the 20th century's most enduring designs. They can be infinitely reconfigured, which means kids' ideas about design can be endlessly reconfigured as well. Famous architects have said they do what they do because of Lego. Nevertheless, the plastic bricks are not pretty.

Tsumiki bricks, on the other hand, are lovely. Tokyo architecture firm Kengo Kuma and Associates made them with forest conservation organization More Trees, and bills them as "Japanese Lego." Unlike Lego bricks, which are plastic, Tsumiki pieces are made of Japanese cedar (and manufactured using wood certified by the Forest Stewardship). And unlike the brick-shaped Lego blocks, each Tsumiki block is shaped like an inverted "V."