Ramune Onsen-kan is a distinctive architectural work completed in 2005, located in Naoto, Taketa City, Oita Prefecture. Designed collaboratively by Masaaki Irie of IGA Architectural Planning and Terushige Fujimori, this innovative structure seamlessly blends art museum and commercial facilities. The building showcases contemporary Japanese architectural philosophy, drawing inspiration from the region's hot spring heritage while incorporating modern design principles. Its unique aesthetic and functional design create a welcoming space that celebrates local culture and contemporary art, making it a notable landmark for architecture enthusiasts studying early 21st-century Japanese design practices.