The history of corrugated boxes goes back to the early 1900s. It is said that they were called paper boxes stronger than wooden boxes and spread all at once amid brisk business after World War I. Now corrugated boxes are familiar packaging materials. When they are evaluated from an aspect of environmental performance, however, they are actually honor students. In Japan, the collection rate of corrugated boxes is as high as 95% and old paper recycling rate at corrugated cardboard factories is an astonishing 90% or more. In truth, materials that clear the cost, process capacity, and environmental performance at as high a level as these as one-way packaging materials have not yet emerged. Corrugated cardboard can be used as exterior materials and processed into the interiors of the complicated structures as shown in the photograph. In addition, Oizuru also has many design records of using resin foam only at a place where the buffer structure is necessary, and recycling both the materials by separating them when the foam is disposed as shown in the example on the left.