Stray Little Devil

Stray Little Devil is a manga series by Kotarou Mori. It was serialized in Dengeki Comic Gao!.

Plot
Meet Pam Akumachi, an energetic 13-year-old junior high student who has just turned into ...a little devil! One day, when Pam and her friends try to summon the "benign devil," the magic circle goes out of control and Pam is transported to a strange parallel world where angels and devils reside in an uneasy coexistence.