Hoki is one of the Eight Great Tengu, as well as Sagami's younger brother. 'Hoki' is his designated name for the post he holds in the Daitengu, but his real name is actually Yûu.
Hoki is usually seen with his eyes closed. He is surprisingly very fond of books and loves reading. Also, he is good at making tea. He has a dark side; where he doesn't innately know the difference between good and evil.
When Hoki was little, he was often alone when he was younger because his parents were in Yoh's Daitengu and his brother was the attendant to Kyo. When Kyo offered his hand to Hoki, he took it and then has followed Kyo ever since.
He comes across as serious but is kind at heart. He is caring and sensible. He likes to help others.
Sagami is Hoki's older brother by nine years; they are both part of the Great Eight. Sagami can sometimes be rather protective over Hoki, especially due to his younger brother's dark side.
Hoki and Misao are acquaintances, brought together by Kyo. He is somewhat protective of Misao, and is first seen when Kyo introduces him to Misao in volume 2.