Groper Train: Wedding Capriccio (1984)

The world's greatest detective, Ippei Kuroda, is back and this time hired by a politician to find his estranged daughter. When the daughter is found dead, the mystery deepens. Meanwhile, Kuroda's assistant tries to stop her arranged marriage to a country hick by shacking-up with a composer who writes symphonies on his calculator - when he's not groping women on the Tokyo trains!