Bokusatsu Tenshi Dokuro-chan

Bludgeoning Angel Dokuro-chan follows Sakura Kusakabe, a junior high student whose future has already been ruined by a crime he has not yet committed. Twenty years from now, Sakura will invent technology that prevents all women from aging beyond the age of 12, with immortality as an unintended side effect. To stop that future from ever happening, the angel Dokuro Mitsukai is sent back from the future as an assassin, carrying a magical spiked bat named Excalibolg. Dokuro, however, refuses to carry out her mission in the usual way. Instead of simply killing Sakura, she decides to keep him in constant chaos, bothering him so relentlessly that he can never focus long enough to create the dangerous technology that would trigger the disaster. Her bizarre methods make Sakura's life far more unpredictable than any assassination order ever could. When Dokuro goes against orders, the angel Sabato is sent to complete the mission. Caught between Dokuro's impulsive violence, her habit of killing Sakura and reviving him with the magic words "Pipiru piru piru pipiru pi," and Sabato's electric baton, Sakura's life is condemned to remain loud, dangerous, and painfully far from peaceful.