The large-scale mixed-use building is located at the northern gateway to Nihonbashi. The design in unison with the adjacent Mitsui Main Building and the Nihonbashi Mitsui Tower creating a new scenery of Nihonbashi, expresses tradition and innovation, harmony and diversity, as well as modernity and the future. The large glass-roofed plaza, which is the symbol of the project, is one of the largest community spaces in the area serving as a local disaster relief base. Commercial facilities, a hall, and conference rooms are located in the low-rise portion. Centering the sky lobby, office support facilities and an outdoor deck constitute the mid-rise portion. The office floors in the highrise portion bear the largest floor plates in central Tokyo. HiDAX-R seismic vibration control dampers equipped with a vibration energy recovery system are utilized as a structural component, and a watertight underground CGS/DHC plant is installed for preventive measures against water damage.