Sixth-grader Kotarou Higuchi faces the daunting task of not only getting into a reputable middle school but also handling the responsibilities that come with living alone in an apartment. His morning routine takes a surprising turn when an unfamiliar older girl dressed in black frills appears outside his door. She introduces herself as Misha and requests friendship, despite Kotarou's initial attempts at brushing her off.
Misha proves to be quite persistent, following Kotarou to school and back. Eventually, he relents and learns that Misha is his new neighbor from Heaven, working hard to become a full-fledged angel. With this "clingy angel" in his life, what kind of adventures and growth will Kotarou experience?
