Tsuzukikekojiyakura (都築家糀屋蔵) is a rare historic building in Koshigaya City, Saitama Prefecture, recognized as the oldest surviving Western-style structure in the city and registered as a National Tangible Cultural Property. The storehouse was built in the early twentieth century by the Tsuzuki family, a merchant household that had operated a miso brewing business since the late Edo period, and originally served as a warehouse for the production and storage of fermented goods essential to everyday food culture. Although constructed of reinforced concrete, the building was designed in the style of a traditional Japanese earthen storehouse, combining modern materials with a traditional appearance in a way that was highly unusual at the time and remains rare within the prefecture today. Notable features include its thick walls and a vault-like entrance door fitted with a dial lock, reflecting fireproofing considerations and the practical requirements of commercial storage. The miso business ceased operations in 1958, yet the building itself has survived as a tangible reminder of local industry and architectural experimentation in the early modern period. Located along the former Nikko Road in the historic Koshigaya-shuku area, Tsuzukikekojiyakura stands within a streetscape that still preserves traces of the old post town. Following renovation in 2020, the building was adaptively reused as a café and multipurpose space, allowing visitors to experience a historic commercial storehouse not as a static monument, but as an active and welcoming place that connects architectural heritage with contemporary urban life.