Nako Kagura, middle school student and aspiring cello player, lives with her ever-so-lively mother in a home that was once a temple used by her mystic ancestors. Little does she know, the catacomb-like basement beneath her home holds an Angel, who has been sleeping for 75 years. As fate would have it, a quick run to the basement leads to her reactivating Steel Angel Kurumi, who is as energetic as ever and just thrilled to have a new 'master'. Unfortunately, Nako's childhood friend Uruka is not impressed, nor is she happy about the newfound bond between Nako and Kurumi. Jealousy is powerful, as is Uruka's family, and they will pull no stops to introduce Kurumi to her demise!