In Kara no Kyoukai 4: The Hollow Shrine when Ryougi Shiki is in a coma after throwing herself in front of a truck, her other persona, SHIKI, seems to trade places with Shiki as she's falling. It's later revealed by Touko that SHIKI gave his life to save Shiki.
So how was it SHIKI saved Shiki while she was in a coma? What was happening to Shiki that would allow SHIKI to trade places and cease to exist?
From the novel, the doctor said that Shiki jumped the instant before the collision, so there wasn't much physical injury. The head experienced some collision thus put her into a coma. Aozaki also states later that SHIKI died spiritually.
From the narrative it seemed that SHIKI died during the collision.
At the end of the chapter, Shiki herself states that SHIKI probably died in a suicidal sense, because he wanted to avoid himself harming KokutÅ.
