Are Yanagawa's house and Nishimachi village house the same family?

No.

Yagawa Tianya and Nishimachi Muraya are not the same company. They are two independent companies, operating different businesses and located in different geographical locations. Yanagawa Tianya is a historic inn located in Yanagawa City, Fukuoka Prefecture. It provides traditional Japanese inn services and provides tourists with accommodation, hot spring baths, food and other services. Nishimachi Muraya is a kimono-based store located in Minami Aoyama, Minato-ku, Tokyo. It focuses on the sales and rental of kimonos, provides services such as purchasing, customizing, and repairing kimonos, and also deals in related kimono accessories and cultural products.