clowick canaan-vail is a one-shot manga written and drawn by Takeuchi Takashi, published in the doujin anthology Angel Voice as one of TYPE-MOON's first public releases. For the same anthology, Kinoko Nasu wrote Notes..
The story takes place in a ruined post-apocalyptic world. Main character is Gabriel, an 'Auto-man', a data terminal in human shape, that works as a postman. At the beginning of the story, she has only five days of operation left before she runs out of power. As the technology to repair/recharge her is lost, that means death for her.