Count Ogasawara Residence is based on a Spanish architectural style rooted in the former Spanish-held territories such as California and New Mexico during colonial times.
Its well-balanced exterior creates an elegant atmosphere using Spanish roof tiles, outside walls with a scraping finish, and tiles with decorated surfaces. An arched opening with grills was included taking the Japanese climate into account, and we can observe further diversions into differing styles, including the entrance canopy with arabesque design and the ornate plaques on the outside walls of the smoking room.
The courtyard with the fountain is said to be one of the finest examples of Spanish-style architecture to be found in Japan. The stairway to the roof garden is placed from the courtyard and creates a three-dimensional line with variations, which was quite unique in residential architecture of that era.
In the details of the residence, one can find decorations in the motif of birds, grapevines, and flowers. These attractive details may be found in the stained-glass windows, window grills, and heat-detection grills.
For the smoking room, decorations of the inside walls, the marble pillars, and flooring are all designs authentic to the period in which the residence was built. The Moorish influenced style interiors, such as the floor composed of marble mosaic tiles, breast walls of colorful sandstone sculptures and colored plaster sculptures are very rare in Japan.