Birthday: October 15
Height: 169 cm
Weight: 60 kg
Blood type: AB
Shiki is the main character of the Tsukihime series. He is a kind, honest, if not slightly playful second-year high school student. He is anemic and is prone to fainting, but he tries his best to live a normal life. He has the Mystic Eyes of Death Perception (Chokushi no Magan), allowing him to see the "Lines" and "Points" that enable him to kill all things using the highly effective assassination techniques hidden in his subconscious. Despite being constantly surrounded by death he has a greater appreciation for life than most people and would never take a human life.
He acquired the Mystic Eyes of Death Perception during childhood while in the hospital, after recovering from a near death incident. He escapes his room to run away to nearby fields, and it is there that he meets the Magus Aozaki Aoko, who Shiki now refers to as Sensei. He was eventually given his signature glasses to seal the power in his eyes as a parting gift, along with unforgettable life-lessons. After leaving the hospital, he lived with the Arima family for 8 years, before being called back to the Toono Mansion by his sister Akiha; after their father passed away and she became head of the Toono family. On the day he was to return to the Mansion, while leaving school early, he notices, stalks, and "kills" the Vampire Arcueid Brunestud in a fit of insanity. He passes out because of the shock, and wakes up in the Toono Mansion later that evening, with nothing out of the ordinary. He passes the incident off as a dream, that is, until being casually greeted by the supposedly dead Arcueid on his way to school the next day. It is then, that his life begins to take a turn of events once again.
He is known as Nanaya Shiki, and is the last of the Nanaya clan of supernatural/demon hunters. He was adopted by Toono Makihisa (Akiha's father), after he had led the massacre of the Nanaya, due to his first name being similar to his own son; "SHIKI". After the near death incident involving Shiki and "SHIKI" in the courtyard, Toono Makihisa tampered with Shiki's memories to make him forget about the Nanaya and the existence of "SHIKI", in hopes of having him maintain the image of his son "Toono Shiki"; to keep up appearances. He had "SHIKI" announced dead (as the adopted Nanaya child) but actually secretly confined, and Shiki sent to live with the Arima (as Toono Shiki), because he was now "unfit physically" to become the next head of the Toono house; a perfect cover up.
While Shiki's Nanaya blood is active ("Nanaya mode"), he gets strong urges to "Kill", which can manifest in not just assassination, but also sexual desire, and destruction. He also re-discovers the hidden techniques and senses he had sharpened as a child. It is usually triggered by encounters with the supernatural, or when he's in a pinch. Over time, he slowly begins to get used to it, and doesn't lose himself as much mentally.
He gets headaches when using his Mystic Eyes of Death Perception excessively, as they put a strain on his brain. If he keeps pushing himself, he can permanently damage his brain, and has been notified of this on many occasions.
In the alternative Visual Novel routes: "Far-side" routes
Shiki doesn't encounter Arcueid, and the story further digs into the conspiracies and mysteries surrounding the current residents of the Toono Mansion; Akiha, Hisui, and Kohaku. As well as Shiki and "SHIKI".
(Source: Wikipedia, Type-Moon Wikia)
Note: "Shiki Toono" is the correct spelling of this name per Hepburn romanization, which is used as a MyAnimeList standard. Please do not submit changes for the name.