SANAA partner Kazuyo Sejima has designed a mirrored express train for Japan’s Seibu Railway company which will be a unique leisure destination in its own right.

The train, which will enter service in 2018, has a reflective surface that allows it to blend almost entirely into any landscape it passes.

The train’s interiors are poised to be as equally significant as its ‘invisible’ facade. Sejima has been tasked with creating spaces where people will actively choose to meet, relax and socialise.

“This will be an express train for everyone, like an intimate living room where people can spend their free time in their own way with a variety of people they want to be with,” said Seibu in a statement. “We aim to provide a new public space, almost park-like, where people will come together. It’s more than just a means of movement, it’s a destination in its own right.

“The train will serve commuters, people seeking relaxation and tourists drawn by its unique appearance.”

The train will run as a limited express service, and is the first new flagship series to be produced by Seibu in 25 years. It was commissioned to celebrate the company’s 100th anniversary.

Sejima – whose Pritzker-winning work with Japanese studio SANAA is currently being celebrated in an exhibition at New York's Museum of Modern Art (MoMA) – is collaborating on the design with Seibu and Japanese conglomerate Hitachi. This is her first train design.

Seibu said: “In order to create a limited express vehicle embracing new ideas, we chose to ask an active, internationally-acclaimed architect, to create a design concept for a train with an unprecedented appearance inside and out.”