Nachdem er versprochen hat, nur ein einziges Mal mit Aria zusammenzuarbeiten, nimmt Kinji zum ersten Mal seit langer Zeit wieder am Unterricht in der Abteilung für Körperverletzung teil. Doch dann wird ein Bus mit den Schülern der Budou High School von den "Budou Killers" entführt und eine Bombe gezündet. "Aria, die den Attentätern sehr feindlich gesinnt ist, macht sich mit Kinji auf den Weg, um die Schüler zu retten.
Aria follows Kinji to the arcade where he manages to win some plush dolls for her. The next day, Kinji and Aria learn that a schoolbus has been hijacked by the fabled Butei-killer and fitted with a bomb that will explode if it slows down with an armed convertible preventing the passengers from interfering. As the busdriver gets injured when an attempt to stop the convertible is foiled by heat-detection, Aria and Kinji arrive on the scene, taking out the convertible. With the bus slowly running out of gas, Aria finds the bomb on the underside of the bus whilst Kinji finds and destroys the communications sensor. The bomb is disarmed by the sniper ace, Reki, but Aria is injured by another armed vehicle whilst trying to protect Kinji. As she is treated in hospital, she feels disappointed that Kinji didn't meet her expectations.
Kinji e Aria vengono coinvolti nel dirottamento di un autobus con sopra degli studenti Butei as opera del Butei Killer. Riusciranno a salvare tutti prima dello scoppio della bomba e a mettersi in salvo? Kinji sarà all'altezza delle aspettative di Aria?
アリアと一回だけ一緒に組むという約束をしたキンジは、久しぶりに強襲科の授業を受けるようになる。
だがそんな折、武偵高の生徒たちを乗せたバスが、「武偵殺し」にジャックされて爆弾を仕掛けられるという事件が発生。
「武偵殺し」に対して強い敵意を抱くアリアは、キンジと共に生徒たちを救おうと動き出す。
Aria sigue Kinji a la galería donde se las arregla para ganar algunos muñecos de peluche para ella. Al día siguiente, Kinji y Aria se enteran de que un autobús lleno de estudiantes Butei ha sido secuestrada por el asesino de Butei y equipado con una bomba que explotará si se ralentiza y un convertible armada impide que los pasajeros de interferir.
