The real father of Tohno Shiki (Shiki's real name is Nanaya Shiki). Was the most recent head of the Nanaya family, until their destruction orchestrated by Tohno Makihisa, and his death at the hands of Kishima Kouma. A highly trained assassin who, like all Nanayas, possessed a form of Mysic eyes. His ability allowed him to see the lines of people's thoughts. How this aided his killing methods was not elaborated.
Personality:
Kiri never actually enjoyed killing. It is hinted that he may found it exciting but he never enjoyed it. Until Shiki was born, Kiri never thought of what he would have his son do as part of the Nanaya Family. Kiri later felt that he did not want his son to follow the path he took (becoming an assassin).
Appearances:
Nanaya Kiri only appears directly in the Kagetsu Tohya side story Red Demon God, which tells his story and is the main source of most things known about him - Tsukihime itself does not even mention his name. In Red Demon God, he is never shown, and so there is no "real" illustration of him; however, the Tsukihime artbook Plus Period has an encyclopedia entry on him, which also includes a sketch of him.
References: ^ Tsukihime Dokuhon Plus Period, page 186