Unbeknownst to average teenager Haruo Yoshikawa, his three sisters have magical powers, which they use to protect him and keep him out of trouble. Everything is going fine until a young witch cursed to lose her powers discovers that Haruo is the boy she needs to break her curse. Now Ayumi Mamiya must awaken the latent powers within Haruo to restore hers. Unfortunately, Haruo?s sisters aren?t going to let her near him without a fight!