Yotsuya Kaidan : Act 4

At the opening Naosuke is pressuring Osode to consummate their marriage, to which she seems oddly averse. Yomoshichi appears and accuses Osode of adultery. Osode resigns herself to death in atonement and convinces Naosuke and Yomoshichi that they should kill her. She leaves a farewell note from which Naosuke learns that Osode was, in fact, his own younger sister. For the shame of this, as well as for the killing of his former master, he commits suicide.