Following the Heath Oslo incident, the existence of the US-Japanese anti-terror organization CIRS has become a matter of public knowledge. CIRS has been rebuilt from the ground up, and its most covert functions spun off to a new agency: SORD (Social Ops, Research and Development). The goal of SORD is to train a new generation of operatives to defend the country against future threats. To that end, the organization has established a series of schools up and down the country. Mihama Academy, more-or-less left to rot after its abrupt closure, has been given new purpose as one such 'specialist training school'. This new incarnation of Mihama Academy is home to a diverse group of students, who every day work to polish their unusual skills - sometimes on the job. Mihama now entrusts the misfit girls who attend it with guns and live ammunition. Paying their own safety no heed, these students are again and again plunged into dangerous extrajudicial missions - all for the good of the realm. "... 由“国家组织CIRS”新设的特殊技能训练校“美滨学园”……因各种原因失去归所的少女们被交付的是，枪与实弹。使用手枪的玲奈、擅长狙击的桐花、炸弹与信息处理的克莉丝、负责谍报活动的忍者邑沙季。她们每天都以SORD成员的身份，处理警察及自卫队无法解决的事件，不断进行着危险的活动。 K县U港——。准备入国的重要人士突然消失了。SORD成员开始调查失踪事件，但每当即将捕获消失的“行李”时，就会在还差一点的时候被其逃脱。与姊妹校“京船樱丘”的SORD成员双子姐妹并肩作战，以及争执。以及——在夜晚的城镇中疾奔的神秘女骑手“Soul Speed”·真纪的传闻——。追踪最终转变成壮烈的死战，将身心一并撕裂。 ……但这同时还是，通往玲奈她们相遇之前的过去的旅程。
