Kurosaki Mea was just starting to feel at home on Earth—but after defeating a pack of interstellar killers, she's once again committed to living her life as a human weapon. Rito and Nana aren't ready to give up on her just yet, though. Even if she's a deadly assassin, they mean to show Mea that love and friendship aren't just skip deep. Amidst the revelry of a school festival, there's just one thing to worry about: the long-dreaded arrival of Master Nemesis herself!