The Old Hachiman Post Office building, completed in 1921, was designed by William Merrell Vories (1880–1964), an American-born architect, missionary, and businessman who lived and worked in Omihachiman for the greater part of his life. The building was the town’s main post office until 1961, after which it was used as an office, a warehouse, and a shop. It then fell into disrepair for several decades before an intervention by local nonprofit organization Hitotsubu no Kai, established in 1997 and dedicated to the structure’s preservation and renovation. The organization has restored the building and rebuilt its original arched entrance, which had been demolished. The Old Hachiman Post Office now functions as a gallery and event space and is open to the public on weekends and national holidays between 11 a.m. and 5 p.m. The building is a registered National Tangible Cultural Property.
 
Vories’s design is an eclectic blend of Spanish colonial and Japanese styles, a combination the architect would employ frequently in his later works. The numerous windows allow plenty of fresh air and sunlight to enter, demonstrating Vories’s dedication to comfort and functionality. On the first floor are the original post office counter, the director’s office and reception room, the distribution room, and the main office area. The distribution room is now occupied by a small cafe. The second floor consists of a rectangular room that was used as a telephone exchange and a smaller room used for taking naps during night shifts. In the larger room, the space beneath the floor was once filled with sawdust and ash for soundproofing and insulation. In contrast, there are gaps above the ceiling and behind the inner walls to keep air circulating through the structure, preventing decay due to humidity.