Shiki is the given name of five distinct characters in the Nasuverse:
- Shiki Ryougi, the protagonist of Kara no Kyoukai.
- Shiki Tohno, the protagonist of Tsukihime.
- SHIKI Tohno, an antagonist in Tsukihime.
- Shiki Nanaya, Shiki Tohno's original name and a unique incarnation of him created by Night of Wallachia in Melty Blood.
- Shiki Nanaya, a major character in Hana no Miyako.