Kannagi: Crazy Shrine Maidens

Plot
Kannagi: Crazy Shrine Maidens(かんなぎ) is written and illustrated by Takenashi Eri. It is serialized in Ichijinsha's Comic REX magazine.

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)