A symbolic honor killing? Tachibana throws his (t)rusty knife at a flashback apparition of his violated girlfriend.
So we have a tale of two hangings. The cops believe that the politician (the father of the journalist character played by Mie Kitahara) committed suicide, but Tachibana knows the truth. Tachibana believes he knows why his girlfriend hung herself, but Makoto knows some of the truth, and Katsumata knows more. As Tachibana plunges back into the criminal milieu in search of the ultimate truth, he realizes the need to tell the police the truth about the politician's "suicide." And wouldn't you know? The person behind that hanging and the one ultimately behind the death of Tachibana's girlfriend are one and the same.
Above, dramatic moments from Rusty Knife. Below, Mie Kitahara can't stand the suspense.