Chino (チノ, Chino) is a kunoichi from the Chinoike clan. She was a member of the Lightning Group. Chino is the only child of En Oyashiro and his wife. As members of the Chinoike clan, they lived in the Valley of Hell. Though life in the valley had been peaceful for many years, being in constant close proximity eventually caused disagreements between clansmen to erupt into violence; only Oyashiro and Chino survived. Oyashiro regretted his role in the deaths of his clan, especially his wife's, and wished for Chino to grow up to be better than he was. To that end, he took advantage of Chino's young age by concealing his relationship to her, instead telling her that he had her entire family killed so that she would become the last possessor of the Ketsuryūgan, and thus a valuable commodity.

Naruto
Moments prior to Naruto Uzumaki's birth, a huge demon known as the Kyuubi, the Nine-Tailed Fox, attacked Konohagakure, the Hidden Leaf Village, and wreaked havoc. In order to put an end to the Kyuubi's rampage, the leader of the village, the Fourth Hokage, sacrificed his life and sealed the monstrous beast inside the newborn Naruto.