Paulownia tomentosa
The standard Hō-an-den should be built near the principal's office, staff room or duty room, outside the building; the minimum interior space should be 85 cm from the front to the back, 1.5 meter high and 1.2 meter in width; construction should be in reinforced concrete, with walls more than 25 cm thick. The Ho-an-den should be equipped with a safe-type door, and the interior should be resistant to fire and earthquake, with asbestos, and covered inside with wood such as "Chamaecyparis obtusa" or "Paulownia tomentosa". The height of the container for the photograph was to be 50 cm.