A man who caused the deaths of a couple in a fatal case of road rage in 2017 that triggered tougher regulations against dangerous driving had his 18-year prison sentence upheld by the Tokyo High Court on Monday.

The court found Kazuho Ishibashi, 32, guilty of causing the deaths of Yoshihisa Hagiyama, 45, and his wife, Yuka, 39, as well as injuring their two daughters due to his dangerous driving on the Tomei Expressway in Kanagawa Prefecture in 2017.

The court was hearing an appeal filed by Ishibashi over the Yokohama District Court's 2022 ruling that found him guilty.