The summer vacation comes to an end, and Suguru, Miyuki, Rin and the others return to school. On the very first day, as they are walking to class, Chizuko is nearly run down by an out-of-control car, but saved by a mysterious man who appears, seemingly out of nowhere, and leaves as quicky. Later in the day, the same man, Tou Ryuga, reappears again, as a substitute teacher hired by the school. But later still, at the mention of his name, Mahoro grows uneasy. The reason, revealed in the evening of the same day, is simple: much like Mahoro herself, Ryuga is a combat android, only in the service of the alien invaders SAINT. He attacks Mahoro as she is out shopping, and although Mahoro and Slash gain the upper hand, she feels that rather than being able to defeat Ryuga, she is merely being allowed to survive. Before he leaves, however, Ryuga declares his intention - to challenge Mahoro and make the final determination of which one of them is the better warrior. During Mahoro's active service, her and Ryuga engaged - inconclusively - several times. Now, though, the first step he takes is finding out just what the nature of the relationship between Mahoro and Suguru, whom he knows to the the son of Commander Ryoh Misato, is. It is to this effect that he infiltrates Suguru's school and interrogates his various friends. The responses are nothing but praise - and in the cases of Miyuki and Rin, blushing and mumbling - although unsurprisingly, Saori misinterprets the situation and perceives Ryoh as a rival for Suguru's affections. Later, Slash and Mahoro, who also infiltrate the school, challenge him. Mahoro threatens to fight Ryuga right there and then, if that would mean protecting Suguru. Whether he is truly concerned or simply looking for an excuse to put the battle off is not clear, but he declares that he is unwilling to fight in a location where civilians could be harmed, and leaves.
Un nouveau professeur, Monsieur Ryûga, intègre l’école. Yû et Fukami sont surpris de reconnaître en lui l’homme qui a sauvé Chizuko d’un accident de voiture ayant eu lieu le matin même. Mais la plus étonnée demeure Mahoro, qui reconnaît en Ryûga un soldat de l’organisation Saint.
여름방학의 마지막과 함께, 스구루의 학교에 부임한 신임 교사 류가가 단상에 서자 스구루와 같은 반 아이들은 놀라게 된다.
그날 아침 탈옥수가 운전하는 자동차에 치즈코를 사람의 재주라고는 생각되지 않게 기민한 행동으로 구해주었던 청년이였기 때문이다.
집에 돌아온 스구루의 화제는 역시 류가… 이 이야기를 들은 마호로의 반응이 이상한데…
Las vacaciones de verano llegan a su fin y Suguru, Miyuki, Rin y los demás regresan a la escuela. El primer día, mientras caminaban a clase, Chizuko casi es atropellada por un auto fuera de control, pero un hombre misterioso la salva, aparentemente de la nada, y se va rápidamente. Más tarde ese mismo día, el mismo hombre, Tou Ryuga, reaparece como maestro suplente contratado por la escuela. Pero más tarde aún, ante la mención de su nombre, Mahoro se inquieta. La razón, revelada en la noche del mismo día, es simple: al igual que la propia Mahoro, Ryuga es un androide de combate, solo que al servicio de los invasores alienígenas SAINT.
