Naka 12th Building No. 6 Newly Built
[Drawing by Ryoichi Kawamoto]

This article introduces the blueprints for Naka No. 12 Building No. 6, which was completed in 1920 (Taisho 9). The stamps reveal that Kawamoto Ryoichi was in charge of the architectural design, and Yamashita Juro was in charge of Structural Engineering, under Chief Engineer Sakurai Kotaro. Kawamoto graduated from what is now the University of Tokyo in 1914 (Taisho 3) and joined the real estate department of Mitsubishi Limited Partnership Company. He was in charge of the Mitsubishi Bank Head Office and Naka No. 12 Building No. 6, and later became involved with Maru Building. After the Great Kanto Earthquake, he changed jobs and became head of the architecture department of the Dojunkai, before going independent and working on projects such as the Okuno Building (formerly the Ginza Apartments), Kudan Kaikan (formerly the Military Hall), and Tamuracho Nissan Hall (no longer in existence).
Let's take a look at the blueprint for Naka Building No. 12, No. 6. It's a four-story building with one basement floor and four aboveground floors, constructed of reinforced concrete. Its floor plan is very simple, with two short spans, wall columns on the perimeter, and a central circular column. While facade has a three-story structure, tall vertical windows are evenly spaced, and the design is geometric and minimally decorated. The plan shows the number of rows of tiles laid vertically, just as it was in the brick construction era. The joint widths, 12mm to 15mm, are larger than those of brickwork, providing a solid, well-spaced joint. The tiles on the basement are not laid in a straight line (where horizontally adjacent tiles are alternately placed, offset by half), but in a straight line (where the tile joints run vertically and horizontally). The columns between the windows have a faux stone finish, with tiles only on the corners. In other words, this breaks away from the traditional rules of tile, which evolved from brick construction, and seems to assert, "Because it's reinforced concrete, we have freedom!" Looking at the Kudan Kaikan (1934), a building he designed later in life and known for its Imperial Crown style, facade tiles are used freely, with protruding and recessed sections on each level, the roof tiles have a blocky shape, and the helmet-like decorations on the capitals of the columns are geometric and Gundam-like. Kawamoto's drawings for Naka No. 12 Building No. 6 are interesting as they represent the early days of the era of free facade design using reinforced concrete and tiles.