Vice-captain of the Archery Club. Shirou's departure from the club was triggered by Shinji pointing out that the injury Shirou sustained at his part-time job was unsightly. Later, forcing the retired Shirou to clean the club room became the catalyst for Shirou getting caught up in the Holy Grail War. According to Shirou, he is a man with "flavor," but he is someone who does not respect others' feelings, readily exploiting people and taking out his frustrations on underclassmen. In official settings, he is actually set as a handsome guy with excellent grades; a model student who respects discipline and dislikes unfairness (though he doesn't follow it much himself). He is popular with girls for being friendly, wealthy, and kind (though he's the type who doesn't feed the fish once caught, making exceptions only for girls he's already won over). He is poorly regarded by boys and some girls. According to Sakura, Shirou is Shinji's only friend. Though he carries the blood of the Matou magi, the Magic Circuits were completely lost by his father's generation. While he has knowledge of magecraft, he cannot use it at all. Since childhood, he was aware of his defect as a magus, yet he took pride in being the heir to the Matou family, believing the fact that he was the legitimate son of a chosen lineage remained unchanged. He lived with the self-esteem that he was a "special existence" different from others. At that time, his personality was merely that of a "talented but arrogant jerk." In the Matou family, Shinji is treated as a non-entity because he lacks magical talent. Consequently, he became unable to maintain his ego except by disregarding others, living only by looking down on those around him. Toward Sakura, who was adopted as an orphan, he satisfied his pride by treating her as a "dull, incompetent, and pitiful sister" who was kept in the dark about the family secrets while he was the heir. Directing pity and looking down on her from a position of superiority was his most reliable source of self-esteem. Because of this, he was able to act as a reliable and kind older brother to her. He cherished and doted on his "incompetent sister" because she provided him with a sense of superiority. In his subconscious, there was always a fear that the Matou family would be taken over by some unknown outsider. Until he learned Sakura was the true successor, he doted on her while bullying her slightly, but after learning the truth, his self-esteem could not survive unless he thoroughly suppressed her. His friendship with Shirou is genuine, albeit distorted, and his proposal for an alliance was sincere. Though Shinji himself isn't aware of it, Shirou is the one he "wants to be a rival to," an "irreplaceable existence he wants by his side," and the "only man who associates with him without calculation." Setting aside likes and dislikes, he views Shirou as special and wishes to clash with him honestly. However, Shirou failed to perceive Shinji's feelings, and out of frustration and loneliness, Shinji developed a twisted obsession with him. It could be described as an overly complex tsundere trait. His resentment after the alliance was rejected can be seen as a yandere-like friendship, stemming from the fact that Shirou chose Rin as a partner over him, despite their past closeness. According to Nasu, he is a man who "would function well if someone were by his side to flatter him." His special skill is not just deduction but "Brilliant Deduction," which is no exaggeration. He sees through the truth from the beginning of the story and presents it to everyone, only to be ignored (especially by Rider). After the shocking trick and culprit are revealed at the end, he gets angry saying, "I told you so!"—he is apparently a pathetic sort of Sherlock Holmes. Regarding Shirou: A best friend since middle school. However, the form of that friendship is unique and far from good. They became estranged after Shirou punched Shinji back for hitting Sakura, leading to a completely hostile relationship. In the main story, his obsession is evident in how he compares himself to Shirou, fixating on who is superior, and how he becomes strangely lively when picking a fight with him. Regarding Sakura: Foster sister. Family and invader. He was once a slightly mean but kind brother, but... He forces his ego onto her, believing that Sakura must never defy him, should remain silent and dejected, and should just do as he says, thereby binding her. Note: There is a rumor online that the author Kinoko Nasu said, "If Sakura had asked for help, Shinji would have saved her," but Nasu never made such a statement. In Character Material, it is mentioned that if Sakura had not pitied Shinji but instead treated him like an insect, they would have become a "Happy Matou Family." Due to his complex character, fans say, "Shinji and Sakura are foster family members who act more like family than real ones; they are siblings on a soul level" (though this makes Rin, Sakura's biological sister, seem quite pitiful). Because of his flavorful personality, some users often say, "If Shinji were a girl, he would have been an invincible heroine." Fans also refer to him as the "Legal Wife" or "The only one who was cheering for that high jump."