Mitsui Fudosan and Kajima Complete Fully Leased Nihonbashi Honcho M-SQUARE
Mitsui Fudosan Co., Ltd. and KAJIMA CORPORATION have completed “Nihonbashi Honcho M-SQUARE,” a jointly developed office building in Tokyo’s Chuo Ward, with the property delivering 100% pre-leased as of November 12, 2025. A line-up of tenants from the space and life sciences sectors has moved in, and the property is now operating as a new cluster hub for these industries.
The building is a 12-story-above, 1-story-below grade steel-framed office asset with a Gross Floor Area of approximately 4,300 tsubo (approx. 153,000 sq. ft.). Fronting Showa-dori Avenue, the property is located about a five-minute walk from JR Sobu Rapid Line “Shin-Nihombashi” Station and Tokyo Metro Ginza and Hanzomon Line “Mitsukoshimae” Station. In addition to a landscaped, greenery-rich exterior, the project provides a rooftop garden with views toward Tokyo Skytree, helping create a highly comfortable work environment for office users. On the sustainability front, the building has obtained ZEB Ready certification for the entire property as well as DBJ Green Building Certification (Plan Certification).
In Chuo Ward, Tokyo, multiple new office buildings scheduled for completion in 2025 have already begun pre-leasing, with the combined newly offered floor area exceeding 5,000 tsubo as of October 2025, according to an editorial analysis based on “estie Market Research.” Against this backdrop of increasing new supply, the fact that Nihonbashi Honcho M-SQUARE achieved full occupancy at completion underlines its relative prominence among newly built assets in the area. The incoming tenants are primarily in the space and life sciences sectors—fields that Mitsui Fudosan is strategically supporting as an “industry developer.” Initiatives pursued through Life Science Innovation Network Japan (LINK-J) and cross U are aimed at building environments that support research and commercialization in these industries, and this property is expected to function as part of that broader ecosystem.
The tenant roster includes JA MITSUI LEASING, KONG STUDIOS, Ubie, SUSMED, and other companies spanning a range of sizes and industries. The landlord and partners expect that cross-industry interaction within the building will help spur new innovation.
Key Facts
Property Name: Nihonbashi Honcho M-SQUARE
Developers: Mitsui Fudosan Co., Ltd.; KAJIMA CORPORATION
Location: 1-9 Nihonbashi-Honcho, Chuo-ku, Tokyo
Nearest Stations: JR Sobu Rapid Line “Shin-Nihombashi” Station; Tokyo Metro Ginza Line and Hanzomon Line “Mitsukoshimae” Station (approx. 5 minutes on foot)
Completion: November 2025
Number of Floors: 12F / B1
Structure: Steel construction (S)
Gross Floor Area: approx. 4,300 tsubo (approx. 153,000 sq. ft.)