Shinjuku Eastside Square

A 20-floor, 96m mixed-use office complex completed in 2012 just east of Shinjuku's entertainment district, directly connected to Higashi-Shinjuku Station. Its unusually large floor plates of roughly 5,900 m² per level and low-carbon design attracted major IT and content companies including Square Enix.

Use

Office tower

Area

Shinjuku City

Completed

2012

Floors

20 above ground, 2 below

Height

96 m

Developer

Mitsubishi Estate

Architect

Mitsubishi Jisho Sekkei / Nihon Sekkei (JV)

A New Business Hub East of Shinjuku’s Centre

Walk east from Shinjuku Station past Meiji-dori avenue and the landscape changes quickly from entertainment to office. Shinjuku Eastside Square, completed in April 2012, occupies a redeveloped block adjacent to Higashi-Shinjuku Station on the Tokyo Metro Fukutoshin and Toei Oedo lines. The 20-storey, 96-metre building is connected directly to the station concourse by an underground walkway, giving tenants a dry commute whatever the weather.

The building’s defining feature is its floor area. At roughly 5,900 square metres per standard floor — among the largest column-free plates in central Tokyo — it was designed from the start to attract large corporate headquarters. Mitsubishi Estate led the development with architectural design handled by a joint venture of Mitsubishi Jisho Sekkei and Nihon Sekkei. Game publisher Square Enix moved its headquarters here at opening, and the building has since established itself as a cluster for IT and creative industries on the eastern fringe of Shinjuku.

Efficiency and Sustainability at Scale

Shinjuku Eastside Square achieved approximately 25 per cent lower CO₂ emissions compared with a comparable Tokyo office building of that era. High-performance insulating glazing reduces solar heat gain, and a hybrid ventilation system combines natural and mechanical airflow depending on conditions. A low-carbon district energy plant in the basement and rooftop green terraces reduce the building’s overall environmental load.

The contrast with Shinjuku’s older west-side towers is intentional. Where Shinjuku Sumitomo Building and Shinjuku NS Building pushed height in the 1970s and 1980s, Eastside Square prioritised floor efficiency and liveability over a dramatic skyline presence. The result is a quiet, functional office district on the east side of one of Tokyo’s most chaotic neighbourhoods — a different kind of Shinjuku well worth exploring on foot.

Summary

Shinjuku Eastside Square, completed in April 2012, is a 20-floor, 96-metre office complex developed by Mitsubishi Estate in a redeveloped block east of Shinjuku Station. Its 5,900 m² standard floors and low-carbon engineering set it apart from the older supertall towers on the station’s west side, making it a blueprint for large, efficient office development in a dense urban context. Higashi-Shinjuku Station is directly below, so the building is an easy addition to any Shinjuku walk.