Kannagi

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...a girl! So naturally this guardian deity is pretty pissed that her tree was cut down, and lives with Jin while she takes out her anger by squashing bugs...er, cleaning the "Impurities".

Included one-shots:
Volume 2: The Amazing Fairy Puniata
Volume 4: Hildegard’s Castle
Volume 5: Mori
Volume 6: Croquis