The answer is Kazuma Kiryu. Rikiya's voice role is played by Kazuma Kiryu, the main protagonist of the Yakuza series. He is a former yakuza who has been trying to live a normal life. However, he is constantly drawn back into the criminal underworld by his sense of loyalty and justice.
Mastering the World of Rikiya Koyama: An Unforgettable Quiz Journey