A truck driver was sentenced Wednesday to three years in prison for hitting and killing a 9-year-old boy while playing the smartphone game "Pokemon Go."

Nobusuke Kawai, 36, admitted to hitting Keita Noritake in Aichi Prefecture last October while preoccupied with the popular augmented-reality game. Prosecutors had demanded a four-year sentence.

The boy, a fourth grade elementary school student, was hit by Kawai's truck in the late afternoon on Oct. 26 when crossing the road at a pedestrian crossing while walking home from school in the city of Ichinomiya. When the truck struck the boy, Kawai was alleged to have been looking at his smartphone placed on the passenger seat.

The defendant's "fault was very malicious," and he routinely played the game while driving, Judge Takahiro Murase said in handing down the ruling at the Ichinomiya branch of the Nagoya District Court.

Kawai's defense team sought a suspended term because the boy did not listen when his elder brother warned him to step back to avoid being struck.

Takatoshi Noritake, the 46-year-old father of the victim, said the three-year sentence is "too light," and he is considering suing the truck driver for damages.

There have been several fatal car accidents in Japan linked to "Pokemon Go" since the game was released last July.