Episode 30

Sango ponders whether or not to steal the Tessaiga, when Inuyasha awakes. They share brief words about how hard it can be to kill a former loved one, and Kagome, awake too, understands that Inuyasha sympathize with Sango over Kohaku because he feels her situation is the same as he and Kikyo, turned against each other by Naraku. Miroku then wakes up and warns everyone that they are surrounded. Indeed, countless demons attack, led by a Kohaku deprived of his memories and will by Naraku. Inuyasha fights the demons, then Kohaku, but refrains from killing him at Kagome's demand.

At everyone's surprise, Kohaku then talks, in a voice devoid of emotion he says that indeed he deserves to die, since he killed to many people, including his family and friends. He stabs himself to try and extract the Jewel shard from his back, but Sango yells at him not to do it and uses her Hiraikotsu to send the Tessaiga flying in the air. It falls back in her normal form of an old katana. Kohaku relents and flees with the demons to Naraku. Sango, still confused, wonders what to do. She then calls Kirara, seizes the Tessaiga and follows her brother, flying.

While her friends follow her by scent, Sango goes to Naraku's castle. She confronts him and demand the return of her brother. She's even ready to throw her own weapon away to see Naraku. Naraku shows her Kohaku, but puts the blame on the Shikon Jewel for all the evil that happened. Enraged, Sango attacks, throwing the Tessaiga at Naraku and using her own concealed blade to slash him. He reveals himself to have borrowed the appearance of the young lord of the castle after killing him. Sango attacks again, but her blade breaks, leaving her unarmed and wounded. Kirara attacks Naraku, to no avail : his poison defeats her. Naraku then asks Sango to serve him : when she (obviously) refuses, he has her brother come and attack her. The Hiraikotsu comes back to Sango, seemingly due to Naraku's will : he doesn't want Sango's death so much as her corruption, which he would obtain if she kills her brother. But, light-headed, Sango realize that there's just no way she can kill her own loved brother, and renounces to pick her weapon. She falls before him, but then he seems to remember who she is, calling her his sister, and letting go of his weapon as Sango's friend arrive on the scene.

As Sango lay in Kagome's lap, recovering, Naraku wonders why she couldn't kill her brother. He seems unable to comprehend how one could love someone more than their own lives. Sango's friends, on the other hand, understand now perfectly well that Naraku isn't after meaningless death, but after the corruption which arise from mistrust and hatred between friends or family. Angered, Naraku attacks, surrounding them with poison. Sango gives her own mask to her brother : this act of selfless love puryfies the Jewel shard embedded in his back. Said shard reminds Kagome that she can locate Naraku, even in the miasma, by the other Jewel shards in his possession. She fires sacred arrows at him, wounding him, to his astonishment. A violent wind arises, and he escapes with Kohaku in the confusion.

As the sun rise, Sango tries to leave her friends, feeling she's unworthy of their trust and might end up betraying them again, but they all say it's alright, and they will help her fight to get her brother back.

Trivia

 * This is the first time Kagome's arrows has been powered by purification.