In the 16th to 17th century, there appeared the Sankai-gura, three-storied slim shape plastered storehouse (Dozo), in the city illustrations. A detailed comparative study of those illustrations revealed a similarity on roof structure between plastered storehouses, town houses and also early modern age castles. As I studied the plastered storehouse development, the Sankai-gura was evolved from interior store rooms in townhouses to independent exterior structures. This independence became one of a force to modify the city planning in middle age to early modern age.
