Hirai Archi Design, founded by Tadashi Hirai in 2014, is an architectural firm based in Kyoto and Hikone, Japan. Tadashi Hirai, an architect with a background from Waseda University, leads the firm. They specialize in the planning, design, supervision, and renovation of residential and commercial buildings, hotels, urban facilities, and more. The firm also engages in regional and urban research and planning, along with various design projects such as illustrations and graphics.