Tsugawa Yibito's resentment toward Konoha stemmed from the fact that he was also a child of war whom Konoha had taken in.
It was during the Second Shinobi World War, and anyone who lived through war inevitably carried scars. Young Tsugawa Yibito had watched helplessly as his family was blown to pieces. Just as he was in complete despair, Orochimaru had pulled him out from the ruins.
Orochimaru hadn't intended to save him, however; he had meant to kill the boy to eliminate any future trouble.
Chapter 195