Seikado Foundation operates the Seikado Bunko, a distinguished cultural institution located in Tokyo. Established in 1924, the Seikado Bunko features an elegant Western-style building designed by architect Kotaro Sakurai. This two-story structure showcases a refined façade that echoes the architectural style of early 20th-century English suburban homes. The foundation also includes a historic mausoleum designed by the renowned British architect Josiah Conder, adding to its architectural significance.

The Seikado Bunko's collection encompasses a variety of classical literary works and historical artifacts, catering to researchers and visitors alike. While the internal reading area remains private, the picturesque gardens offer a serene environment, showcasing seasonal flora, including plum trees and selected trees recognized in Setagaya City. The foundation regularly hosts exhibitions and maintains a museum shop, providing resources for those interested in exploring Japan's literary heritage. Engaging educational programs and guided tours make the Seikado Bunko a vital cultural hub in the region.