Kannagi

Kannagi: Crazy Shrine Maidens (かんなぎ, Kannagi, lit. "Shrine Maiden"), is a manga series written and illustrated by Eri Takenashi. The manga began serialization in the January 2006 issue of Ichijinsha's shōnen manga magazine Comic Rex. A 13-episode anime adaptation produced by A-1 Pictures aired between October and December 2008 in Japan. An original video animation episode was released in May 2009. Bandai Entertainment licensed the manga and anime series, including the OVA.

Plot
Our unlucky protagonist, Jin, uses the trunk of a sacred tree to carve a statue for a school project. When he takes it outside, to his surprise it begins absorbing the surrounding earth and transforms into, hold your breath on this one, a girl! So like all similar setups this guardian deity is pretty pissed that her tree was cut down and lives with Jin while she takes out her anger on squashing bugs....er, cleaning the "Impurities".

Official

 * Anime official website
 * A-1 Pictures

Other Sources

 * Wikipedia
 * Anime News Network (manga)
 * Anime News Network (Anime)