Those executed were former crime syndicate member Keizo Okamoto, 60, and ex-investment adviser Hiroya Suemori, 67, the Kyodo news agency reported, citing the ministry. Both were sentenced to death for a robbery and murder committed back in 1988.
"It was an extremely cruel case in which they robbed the victims of their precious lives for selfish reasons. [The executions] were the result of numerous careful considerations," Japanese Justice Minister Takashi Yamashita said, as quoted by Kyodo.
The agency also noted that 15 people were executed in Japan in 2018, which was the highest number since 2008.
Japan’s death penalty system has been criticized by human rights organizations from across the world. However, polls suggest that over 80 percent of Japanese nations support capital punishment.