C-1 is a residential and office building completed in 2005 in Shibuya Ward, Tokyo. Designed by architects Guenaël Nicolas and Tomoyuki Utsumi, this structure represents a thoughtful integration of living and working spaces in an urban context. The building showcases contemporary design principles while addressing the practical needs of Tokyo's dense residential environment. Its completion at the height of the 2000s architectural movement reflects the era's emphasis on multifunctional spaces and efficient urban design. The collaboration between the French and Japanese architects brings a distinctive perspective to Tokyo's architectural landscape.