He was not only troubled, he was seriously embarrassed.

The hint thrown out by his little brother about the Koshare had struck him; for it led to the inference that the child had knowledge of secret arts and occult practices of which even he, Okoya, although on the verge of manhood, had never received any intimation.

Far more yet than this knowledge, which Shyuote might have obtained through mere accident, the hint at unpleasant relations between Okoya and the Koshare startled the latter.
It was perfectly true that he not only disliked but even hated the cluster of men to which the name of Koshare was given in the tribe; but he had concealed his feelings as carefully as possible until now.

Only once, as far as he could remember, had he spoken of his aversion; and then it was during an absolutely confidential conversation with his own mother, who seemed to entertain like sentiments.
To his father he had never uttered a word; because his father was himself a Koshare.

Whatever Shyuote knew, he could only have gathered by overhearing a conversation of the Koshare among themselves, in which it was mentioned that he, Okoya, harboured ill-feelings toward that brotherhood.