Maezawa, 45, who made his fortune in online retail, said he plans to document the mission and share it with the world on his YouTube channel with over 700,000 subscribers.
The Roscosmos space agency said Maezawa would make the flight from the Baikonur cosmodrome in Kazakhstan with production assistant Yozo Hirano aboard a Soyuz MS-20 spacecraft that is scheduled for Dec. 8.
“I’m so curious ‘what’s life like in space?’ So, I am planning to find out on my own and share with the world on my YouTube channel,” Maezawa said as quoted by Roscosmos.
The excentric billionaire has previously announced plans to take eight people with him on a 2023 mission around the moon aboard a Starship spacecraft built by SpaceX, the Roscosmos rival of U.S. billionaire Elon Musk.
Maezawa and film producer Hirano will begin approximately three months of pre-flight training in June at the Yuri Gagarin Cosmonaut Training Center in Star City, a closed city outside of Moscow, Roscosmos added.
They have already passed the required medical examinations, it said.
Roscosmos said the flight will last 12 days and the crew will be led by Cosmonaut Alexander Misurkin, who has already been on two expeditions to the ISS.
A total of eight private self-funded space travelers have visited the ISS and Maezawa will be the first from Japan.
His flight will also be the first time that two of the three spots on a Soyuz space rocket will be occupied by tourists.
“We are excited for Maezawa-san and we are honoured to have enabled this opportunity for him to fly to space,” said Eric Anderson, CEO of Space Adventures, a private spaceflight company.
It has cooperated with Roscosmos since the first space tourist flight in 2001.
Plans for first space film feature
Roscosmos separately announced Thursday it was sending an actress and a director to the ISS in October with the aim of making the first feature film in space.
The film, whose working title is “Challenge” is being co-produced by the flamboyant head of Roscosmos, Dmitry Rogozin, and state-run network Channel One.
The annoucement follows one last year by NASA which confirmed that it will be teaming up with actor Tom Cruise to make a Hollywood movie on the ISS.
Maezawa will be the first space tourist to travel to the ISS since 2009 when Canadian Guy Laliberte, co-founder of Cirque du Soleil, traveled to the station.
According to Forbes magazine, space tourists could pay anywhere between $20 and $35 million per person for 8-12 days in space. The cost of Maezawa’s flight has not been disclosed.
The resumption of tourist flights comes after Roscosmos lost its monopoly for ferrying crews to the ISS when a reusable SpaceX rocket last year successfully delivered NASA astronauts to space.
The industry is meanwhile beset with corruption, including multiple scandals over the construction of the new Vostochny launchpad in the Far East.
Russia launched the first artificial satellite on Oct. 4, 1957. The Soviets maintained their lead in the initial years of the race.
They boasted the first manned flight to space by Gagarin on April 12, 1961, the first spacewalk four years later by Alexei Leonov and the first lunar probe in 1966. But the United States beat them to the moon with the first manned landing in 1969.