OMA has unveiled plans for its first building in Tokyo – a glass skyscraper with an elevated garden, which will form part of an emerging business district in the Japanese city.

Designed by Shohei Shigematsu, director at OMA's New York office, Toranomon Hills Station Tower will form part of the new Global Business Hub at Toranomon Hills.

The skyscraper is one of three mixed-use blocks proposed by Japanese property developer Mori Building for the district. It will sit above a new subway stop that will open in time for the 2020 Tokyo Olympics.

"Toranomon Hills Station Tower serves as a key node that connects the new station to the other towers and the surrounding district," said Shigematsu.

"The axis of activity is designed to run through the base, extending vertically to wrap the tower; communicating the activity of the complex at an urban scale."

The mixed-use building will contain offices, hotel accommodation and shops, as well as the new Hibiya Line subway station.

An elevated park will be incorporated into the lower floors of the tower, linking it to the new pedestrian boulevard of Shin Tora Dori.

The other two blocks proposed for the site will be designed by different architects, and are tentatively named Toranomon Hills Business Tower and Toranomon Hills Residential Tower.

OMA is led by Dutch architect Rem Koolhaas, who recently spoke to Dezeen about his longstanding friendship with the late Iraqi-born British architect Zaha Hadid.

The firm, which has offices in Rotterdam as well as New York, has recently unveiled plans for its first project in Dubai, a scheme that will transform four warehouses into a multi-purpose venue for cultural events and a trio of residential towers beside the bay in Miami's Coconut Grove neighbourhood.

Among OMA's most recently completed projects is its Timmerhuis complex in Rotterdam, a reconfiguration of a 1950s office block, and the renovation and expansion of the New York studio of famed Chinese artist Cai Guo-Qiang.

The Toranomon Hills Station Tower is due to open in 2022, but a partial subway service will begin ahead of the 2020 Tokyo Olympics.