Domaine de Mikuni, completed in 2007 and designed by the Sakaura Atelier, represents a thoughtful adaptive reuse project in Karuizawa, Nagano Prefecture. The renovation breathes new life into the historic Iihashi residence while seamlessly blending residential and commercial functions. Located in the charming town of Oiwake, this project exemplifies contemporary Japanese architectural philosophy that respects heritage structures. The design carefully balances preservation of the original character with modern amenities, creating a compelling case study for sustainable adaptive reuse in heritage contexts. The integration of commercial space with residential quarters demonstrates innovative spatial planning suited to contemporary lifestyle needs.