The Wild Reporter (1959)

Original title: 清水の暴れん坊

Seven years ago, Ishimatsu Toshio, a talented radio producer at Zen Nihon Hōsō, witnessed a crazed drug addict murder his wife and then commit suicide, though Toshio was able to save the lives of their two children. Just transferred from Shimizu to Tokyo, Toshio hopes to produce a program that will expose the drug trade in Tokyo. One day, Toshio stops into a noodle shop where he is mistaken for a drug dealer and passed a bagful of drugs. The real dealer arrives in time to follow Toshio home. That night Toshio is attacked by the dealer, who turns out to be Kenji, one of the children Toshio had saved. Kenji can't bring himself to kill Toshio, so he runs away and goes into hiding from the mafia. While continuing to investigate the drug trade, Toshio searches for Kenji to get Kenji's testimony for his program.