Gohiki no shinshi / Cash Calls Hell (1966)

Oida is spending his last days in jail after he caused the death of a man and his young daughter in a car accident he provoked.
Having nothing to lose, he accepts the offer of one of the inmates: to contact a lady who will give him the names of three men to find and to assassinate. Oida soon realizes that he’s not the only one on the job: two professional killers coming from Hong Kong are also looking for the same men to eliminate them. Who really are those three targets? Oida will soon find out.