Among the designer's most high-profile hits is the luxury sleeper train Seven Stars in Kyushu which went into service in 2013. Operator JR Kyushu, in September, announced new routes in southwestern Japan for the train starting in March 2026.

Reflecting on the design of the Seven Stars, Mitooka says he was asked by the head of JR Kyushu to design the best train in the world. He was skeptical about the prospect of success. “I didn’t think it would sell. I honestly wasn’t sure there were people with enough money to afford the ticket prices,” he said.

Plans for the train faced opposition, including from within the transport ministry, according to the designer, who said some opponents labeled it the “crazy train.”

Over a decade after its launch, however, the appeal of the Seven Stars in Kyushu continues to spread, including among observers abroad. In September, the train was recognized as an example of “cool Japan,” collecting an inbound category Cool Japan Award.

The awards were organized by the non-profit Cool Japan Association which seeks to highlight Japanese products and culture that resonate among foreign audiences. The selection process for the award winners in 2025 included screenings by 100 international judges.

Despite what Mitooka sees as the Seven Stars’ cool Japan elements, including traditional shoji sliding panels and kumiko latticework, he thinks it is more easily identified with the Belgian-designed Orient Express.

The iconic train, which also appeared in popular culture as a setting in Agatha Christie’s 1930s mystery novel Murder on the Orient Express, was presented as the benchmark when he began designing the Seven Stars.

To achieve that kind of standard, Mitooka says, it is necessary to break from conventional thinking. “We have to draw up plans for things people say cannot be done and go for it. That is the only way.”

While passengers feel the impact of Mitooka’s designs inside the train, there are implications for the regions it travels through.

As Japan’s growth as a tourism-oriented country gathers pace, governments and private companies are trying to encourage visitors to explore beyond the most famous attractions. Mitooka believes that sightseeing trains play a unifying role in improving the environment of the country’s regional destinations, particularly when consensus in town planning and revitalization can be hard to achieve.

“If the design is right, a one-of-a-kind train can energize communities along the line, and people will come from far away to ride it,” he said. “The environment around the entire line changes.”

This article was submitted by a contributing writer for publication on Japan Wire.