Kohaku is Sango's younger brother and the son of the okashira (leader) of the taijiya (exterminator) village. When a
group of the taijiya was called to do an extermination at a castle, his father took Kohaku along for the first time. Not in
control of his own mind, Kohaku brutally slew his father and comrades and severely wounded Sango, who was also thought dead.
Before perishing from his wounds Kohaku came back to himself, however, and whispering that he was afraid he died in his sister's
arms. Naraku was not finished with Kohaku yet. He revived the boy by placing a Shikon shard in his flesh, wiped away his memories,
and now keeps him as a servant.