It's difficult to conquer the globe, and the mysterious Il Palazzo, head of the ACROSS organization, understands this, so he plans to start small by taking Fukuoka. Two teenage policemen, Excel and her companion Hyatt, are entrusted with carrying out this plot, but they are thwarted by the City Security personnel, a crew made up of three (mostly) regular males, a very serious female, and several robots. Regardless matter how simple their tasks are, Excel and Hyatt always manage to botch them up, which typically results in death and a lot of havoc. Heppoko Jikken Animation ExcelSaga follows the intricate misadventures of the ACROSS officers, as Excel and Hyatt never fail to accomplish their tasks incorrectly.