Orokamonogatari 

Yotsugi Ononoki, the shikigami girl assigned to watch over Koyomi Araragi. This dead tsukumogami girl faces a challenge, but what exactly is that do-or-die struggle with her life on the line? As the "story" grows, it keeps on running, ever burning bright! These are the modern-day oddities! Oddities! Oddities! Youth is going back and forth between pain and peace. (Source: Kodansha, translated)