Kohaku(琥珀）is a character from the manga/anime InuYasha. Kohaku translates to the english word for Amber.
Kohaku is the younger brother of Sango. When Kohaku turned twelve, he was told by his father that he must now put his training as a taijiya to use and help the rest of his family (who are also demon hunters) with their next mission: Exterminating a Spider youkai who is tormenting a small village. Kohaku is scared, but he does not want to disappoint his father. However, during the mission something goes horribly wrong. Kohaku becomes a puppet of the Spider youkai, who has taken the form of the Castle's Lord, and kills his family. Sango sees the spider thread the demon is using to control Kohaku connected to the back of his neck and knows he is not himself. Sango tries to wake her brother up and a battle ensues. They fight until the false Lord orders them killed. Sango is wounded and Kohaku is released from the demon's spell. He rushes to aid Sango, only to be shot dead by the Lord's archers.
Later on in the series Kohaku is brought back to life by Naraku,and is kept alive by a shard of the Shikon no Tama lodged in his his back. He remembers nothing of his past life and so, he becomes Naraku's servant. In episode 29 of the anime (Volume 11 of the manga) Naraku uses Kohaku's life as leverage to try and persuade Sango to steal the Tetsusaiga for him. Later on in the series, some of Kohaku's memories gradually return to him, but he still mostly serves as a minion under Naraku.
Kohaku has two outfits, which he wears throughout the series. One is a short type of kimono, bound by a white sash. The second is a suit of taijiya armor. His main weapon is a version of a Kusari Gama known as a "Chain-Blade", however when dressed in his taijiya armor, he carrys a katana on his sash as well.