Shu and Tsubaki were born in a family of assassins, however, Shu desperately wants to be a chef. The problem is, his food kills who ever eats it. Fortunately, Yuuka, Tsubaki's classmate, and the rest of her wacky family, are determined to get to the bottom of why the food kills everyone, and make sure that Shu's restaurant lives another day.
凶華たちの住む町に、柊雨と椿姫の兄妹が切り盛りする謝々飯店という中華料理屋があった。だが、謝々飯店では料理を食べた客がなぜか笑いながら昏倒するという事件（？）が起きていた。その事件に困り果てた兄を見て、同じ学校に通う優歌に助けを求める椿姫。それを聞いた凶華たちは、謝々飯店に乗り込んで…。
