These are PP (polypropylene) boxes for organizing small items at home which are difficult to organize.
By satisfying molding conditions to prevent deformation, thick shells in simple shapes have been achieved.
A combination of boxes in four sizes can fit into a drawer of any size.
The cross section of each box is angled so that the box is flared toward the top.
The angled boxes contributed to reducing the size of each delivery carton by more than 50%, substantially cutting distribution costs and enabling competitive pricing.

Good Design Award 2004
Good Design Long Life Design Award 2015