It is the year 1648 of the Testament Era. Aboard the Far East's massive ship Musashi, the students of the Musashi Ariadust Academy are challenged by their homeroom teacher Makiko Oriotorai to land a hit on her before she reaches her office across town. Despite all of their advanced skills and unique efforts, none of them succeed. At the end of the race, the class president Tori Aoi, one with a raunchy personality, arrives to reveal that he will propose his love to his childhood friend Horizon Ariadust, which confuses his classmates as she had officially died ten years before.