About Otemachi One

The one and only place for the continual creation of new value

Mitsui & Co. and Mitsui Fudosan have decided to name the project "Otemachi One." This name symbolizes the characteristics of the development area as a place for the convergence of various people and talented individuals, and as the one and only focus for the continual creation of new value from the Otemachi 1-Chome District to the world. There will be a grand opening for the Otemachi Mitsui Hall and a shopping area with approximately 30 commercial outlets. At the same time, Mitsui & Co. will relocate into its new Head Office building. Subsequently, the Four Seasons Hotel Tokyo at Otemachi will open. Thereafter, tenant companies will begin to move into the development in phases.

Facility information

Otemachi Mitsui Hall

With a glass wall approximately seven meters high, the Otemachi Mitsui Hall provides superb views of the greenery surrounding the Imperial Palace. It consists of a hall with an area of approximately 700m², and a 380m² foyer. The facility is ideal for uses ranging from business events such as international conferences and sales presentations to live music performances and other types of entertainment. It will be an important new hub for the promotion of business interaction, international exchange, and access to culture and art.

Otemachi Mitsui Conference

The Otemachi Mitsui Conference is in a great location directly connected to Otemachi Station. In one of Japan's leading business districts, we have eight large and small conference rooms that can accommodate training, meetings, and seminars for up to 300 people. Dedicated staff will support you from the time of inquiries to the day of the event by providing the best proposals for your event.

Four Seasons Hotel Tokyo
at Otemachi

Four Seasons Hotel Tokyo at Otemachi offers an unprecedented luxury experience in the city with the sharp contrasts between the old and the new. In addition to business travelers, the hotel's prime location facing the beautiful Imperial Palace makes it ideal for the base of not only business use but also sightseeing.


Along with the convinience of the direct connection to the Otemachi subway station, the buildings are filled with a wide range of restaurants and cafes that meet a variety of users' needs, as well as facilities such as clinics and running stations which support the health of office workers. The property is designed as a "place where you can feel the change of the seasons and the wind, even though it is underground," and features the only open, high-ceilinged space in Otemachi.


Otemachi One Garden is located in Otemachi, one of Japan’s most prestigious office areas.
The 6,000 m² of verdant green space compliments the greenery of the Imperial Palace spreading out before you and contributes to the surrounding environment by creating a cool and refreshing spot in the city center, aiding efforts to achieve carbon neutrality, and promoting biodiversity.
It is equipped with an approximately 3,000 m² event-ready lawn space, which is rare for the Otemachi area, creating a lively atmosphere in the Otemachi One area.

Service information

Wi-Fi spots

We have a free Wi-Fi connection spots inside the building.
<Wi-Fi area>B2F-4F
*Unavailable in some parts of the areas
<Connection time>30 minutes
*Available multiple times by reconnecting

Multipurpose restrooms

They are located on the 3rd and 4th basement floors.

Baby care room

It is located on the first basement floor for baby care, such as breastfeeding and changing diapers.

Smoking area

Otemachi One is a non-smoking building. Smoking spaces are located on the first and second basement floors.