Prosecutors sought a 23-year prison term for a 26-year-old man on Monday over an alleged road-rage incident near Tokyo last year that left a couple dead and their children injured.

Kazuho Ishibashi's action was "persistent and malicious," the prosecutors said at the Yokohama District Court, while family members of the victims — Yoshihisa Hagiyama, 45, and his wife Yuka, 39 — also called for a strict penalty.

Ishibashi was initially arrested on charges including negligence resulting in death and injury, but the prosecutors applied a stricter charge of dangerous driving resulting in death and injury over the incident on the Tomei Expressway in Kanagawa Prefecture on June 5, 2017. Ishibashi has pleaded not guilty.