Sakura Kusakabe, a junior high student, committed a heinous act. Or, more accurately, he will commit a crime 20 years in the future. What is the alleged crime? He will prevent all women from maturing past the age of 12, with the unexpected consequence of immortality. As a result, the angel Dokuro Mitsukai is dispatched from the future as an assassin, armed with Excalibolg, a magical spiked bat. Dokuro, on the other hand, prefers a different way to killing him. She pledges to be a continual annoyance to Sakura in order to keep him from concentrating on anything long enough to develop his criminal technique. With Dokuro defying instructions, the angel Sabato is dispatched to accomplish Dokuro's job.