Iwane: Sword of Serenity (2019)

Iwane, Kinpei and Shinnosuke are childhood friends. They also trained at the same dojo, hung out together and dreamt together. Iwane, Jinpei and Shinnosuke also become relatives through marriage. Her husband exacts revenge and kills her when news spreads that one of the men's wives is cheating. The woman's brother next rises in vengeance, which leads to murder, which brings about an order of retribution in turn. The woman's affair is becoming a bloodbath.