Signal to Kohaku is the 222nd chapter of InuYasha manga.
Synopsis
Sesshōmaru and Inuyasha continue to battle Naraku. In a cloud of miasma, Naraku makes his escape, saying he will withdraw for now. Sesshōmaru is about to transform and pursue him, but then Naraku mentions Rin and he rushes off to save her.
Sango and Miroku are still trying to get into the hut where Kagome sensed Kohaku's shard. They see him running away with a young girl (Rin).
Inuyasha and the gang reunite. Inuyasha explains what's happening, that Kohaku will probably try and kill Rin.
Naraku orders Kohaku to kill Rin. Sesshōmaru arrives, about to attack the boy.
