This retrospective marks the 25th anniversary of "Inuyasha" by revisiting one of the anime's darkest and most influential storylines, centred on the demon slayer Sango and her young brother Kohaku. The article argues that this arc, though a departure from the show's central romance between Inuyasha and Kagome, is crucial to the series because it establishes the horror at the heart of the story and sets up its main villain, Naraku, whose manipulations drive much of the subsequent plot.

The storyline begins in the episode "Enter Sango the Demon Slayer," when Sango's entire village of demon hunters is wiped out after her 11-year-old brother Kohaku is possessed by a slain spider demon and turned into a killer, ultimately dying himself. It later emerges that Naraku orchestrated the massacre and framed Inuyasha for it, before resurrecting Kohaku as his servant. This leads to further anguish in "Sango's Suffering and Kohaku's Life" and "That Unforgettable Face!", as Sango is manipulated into betraying her friends and is driven to consider killing her brother and herself, cementing Naraku's role as the series' central antagonist.