The move provides continuity and senior leadership as the country’s carmakers grapple with the shift to carbon neutrality.
Akio Toyoda, in his role as chairman of the Japan Automobile Manufacturers Association, expressed shock and sadness at the killing.
The veteran communications executive is back at the automaker after her shocking 2015 arrest in Japan on suspicion of drug possession, resignation and release 20 days later without being charged.
The investigative committee tasked by truck and bus maker Hino Motors blamed the scandal on an environment where engineers did not feel able to challenge superiors, in a rare criticism of corporate culture in Japan.
Toyota says it needs to offer a variety of powertrains -- such as hybrid and fuel cell vehicles -- to suit different markets and customers.