Kumamoto Castle was constructed by Kato Kiyomasa in 1591 to 1606. Furumachi, the neighborhood where Purely is located, is said to have existed even before the castle was built. Furumachi was a merchant town, full of shops pedaling goods that lent the names to each neighborhood that they lined: Komeyamachi (rice sellers), Saikumachi (craftworkers), Gofukumachi (tailors), Kaijiyamachi (metalsmiths), and so on. Goods were still shipped by boat back when this house was built, and the Tsuboi River just behind Purely was a major artery for regional distribution. The legacy of this is still evident in the basement of the Purely Restaurant, where there is a stone wall that is said to have been formerly used as an anchorage point for a moneychanger.

The previous building burned down during the Satsuma Rebellion (1877) during the Meiji Period, but it was rebuilt and then later renovated into Purely in 2005. While the building again suffered tremendous damage during the Kumamoto Earthquakes of 2016, in 2017, the building was once again renovated using a design by Mr. Nobuhiko Sakai of the Fudo Design Architectural Office. This renovation kept the quality old-fashioned elements intact to complete the current Purely building.