Lupin the 3rd S02 E131 Two Goemons - the Mystery of Zantetsuken

A nationwide warrant is out for Goemon, who not only robbed a bank but also stabbed a security guard to death. The Zantetsuken in Goemon's hand has none of the blood-clouding on the blade that would indicate stabbing a person. This is the work of Goemon's archenemy, Nidaemon. There are two Zantetsukens, a male and a female variety. According to tradition, unless the two blades lay together once every 300 years, the larger, male blade will lose its potency. This time is Midnight straight up. Will the disgrace be cleared up?