Negami had been accused of causing the death of a 39-year-old woman in a traffic accident, just after playing the Pokémon Go game in traffic.
The incident took place in September in Nagaokakyo, Kyoto, when Negami, driving his truck-mounted crane, halted at a red light at an intersection.
The Pokémon Go iOS and Android app launched in select countries including the United States and Japan last July, and has since launched in more than 100 countries and territories.
Negami thus failed to assess the safety of his own vehicle.