According to Discovery News, trains with this design should roll out by 2018 and will run "limited express routes." Right now, the train is still in the "concept" stage.
Designer Sejima is looking forward to the day her creation takes the "railroad." In her interview, she says, "The limited express travels in a variety of different sceneries, from the mountains of Chichibu, to the middle of Tokyo, and I thought it would be good if the train could gently coexist with this variety of scenery. I also would like it to be a limited express where large numbers of people can all relax in comfort, in their own way, like a living room, so that they think to themselves 'I look forward to riding that train again.'”