The series 'Tsugunai' follows a young man's twisted journey of revenge. After his beloved sister, Nana, is brutally gang-raped by a group of wealthy delinquents, he is consumed by a singular, burning desire for retribution. He meticulously tracks down each perpetrator, not to kill them, but to subject them to a fate far more intimate and degrading. He targets their mothers, sisters, and girlfriends, using blackmail and force to systematically violate them. The narrative delves into his psychological transformation as he forces himself upon these women, each sexual act a perverse form of 'atonement' for their male relatives' crimes. He films these forced encounters, relishing in their humiliation and terror. One particularly notable conquest is Aoi, the sister of a principal attacker, whom he dominates in a raw, aggressive scene. The series culminates in a shocking climax where the protagonist's own sister, horrified by the monster he has become, confronts and ultimately kills him, ending his depraved crusade.