Staircase, Metal Railing, and Wood Tread Bookshelves add extra utility to the undulating staircase in Tokyo's 921-square-foot Coil house. The space was designed by architect Akihisa Hirata for Sakura and Ryo Sugiura, a young couple with two children.  Photo 3 of 3 in This Sculptural Staircase Shapes an Entire Home