Shirō Emiya, a survivor of the Fuyuki fire, was adopted by Kiritsugu Emiya. This childhood trauma instilled deep survivor's guilt and a fervent desire to help others, shaped by Kiritsugu's ideal of becoming a "Hero of Justice." Kiritsugu imparted basic, incomplete magecraft training, stressing its secretive use solely to benefit others. Following Kiritsugu's death, Shirō lived under the guardianship of Taiga Fujimura and her grandfather, Raiga Fujimura. At Homurahara Academy, he gained a reputation for constant helpfulness and joined the archery club, later leaving due to an injury. During his recovery, Sakura Matou began assisting with chores at his home, becoming a regular presence.

In the alternate universe of the spin-off, where the Fifth Holy Grail War concluded peacefully, Shirō lives without conflict alongside former allies and rivals. Residing in Fuyuki City with his contracted Servant, Saber, he frequently interacts with others like Rin Tohsaka, Sakura Matou, Illyasviel von Einzbern, and various Servants who often visit his home. His central focus is preparing daily meals for this extended family and friends, demonstrating expertise in both Japanese and Western cuisine. Each dish he creates – from New Year's Eve soba and spring chirashi-sushi to heartwarming stew – showcases seasonal ingredients and traditional methods, with recipes often detailed for clarity.

His cooking serves as a profound expression of care, fostering bonds and communal harmony. Food becomes the essential medium for connection; he explains that sharing soba, for instance, symbolizes enduring togetherness. Maintaining a calm, nurturing demeanor, he frequently teaches culinary skills, guiding Sakura in kitchen tasks or collaborating with Rin on recipes. These interactions emphasize everyday tranquility, a stark contrast to his past struggles. This alternate setting highlights his domestic contentment, where providing nourishment fulfills his drive to help, replacing the pursuit of heroism with peaceful resolution.