Two inmates were hanged in Tokyo on Friday in the second round of executions to be approved by the Liberal Democratic Party-led administration of Prime Minister Shinzo Abe.
The inmates were Yoshihide Miyagi, 56, and Katsuji Hamasaki, 64, the Justice Ministry said.
Members of a yakuza syndicate, the pair were convicted of conspiring with an accomplice to gun down two rival gangsters at a family restaurant in Chiba Prefecture in 2005.