The Mole Song: Final (2021)

Kikukawa Reiji is suddenly appointed to infiltration investigator Mole. His mission is to infiltrate the biggest yakuza organization in Japan and approach Todoroki Shuho, who is the head of the organization. Kikukawa Reiji's final mission is to prevent the smuggling of 600 billion yen of drugs. For his mission, he gets on luxury passenger ship and he faces his strongest enemy to date.