Nankoin was a tuberculosis sanatorium established in 1897 by Dr. Takata Koan. By the Taisho period (1912–1926), eleven wards had been built, and it was proclaimed the best tuberculosis sanatorium in the East. This ward is a two-story wooden building built on the north side of the site, and has a rectangular plan with a gable-roofed entrance on the north side and a stairwell on the west side to add variety to its facade. The exterior walls are clapboarded and lined with upper and lower windows, with pediments adorning the second floor windows to provide plenty of openings for lighting and ventilation. It has been recognized as a rare Meiji-era tuberculosis ward in Shonan, which is known as a prominent convalescent area.