Fate/Stay Night

Saber refers to Shirō as her Master, which puzzles him, before she runs off to battle Lancer. She is wounded by Lancer's Noble Phantasm, from which she deduces his true identity, the ancient Irish hero Cú Chulainn. Lancer voices his disappointment at that before leaving, citing that his Master specifically ordered him to return. Shirō and Saber then introduce themselves to each other, though Shirō finds himself confused by Saber's strange terminology. Saber then attacks an approaching Rin and Archer, but is stopped by Shirō, though not before she badly injured Archer. After Rin discovers Shirō does not know even the most basic of spells, or the fact that he is a participant in the Holy Grail War, she takes him to a magus and her legal guardian, Kirei Kotomine, the overseer of the Fifth Holy Grail War. Shirō learns more about the Holy Grail War from him and decides to join it after learning the fire he survived ten years ago was a product of the previous war. Afterwards, Shirō, Saber, and Rin are confronted by the same silver-haired girl Shirō encountered earlier, who is accompanied by a massive Servant.