This story is about a young boy named [url=/c72]Toono Shiki[/url] who, after experiencing a traumatic accident, wakes up in the hospital with the ability to see lines and cracks in every surface and being. These lines, when traced with any sharp or blunt edge, will be permanently cut. As he is forced to see these lines everywhere, Shiki is distraught until he meets a mage girl who gives him glasses that allow him to live a normal life. Years later, after living in a relative's home, the death of his father has him summoned back to the mansion he left years ago. There he must learn to live with his younger sister and two maid girls. One day Shiki's life takes a turn for the worse when, on the way to school, he meets a blonde woman and he's overcome with the urge to kill her.

In the bustling city of Fuyuki, a secret battle rages in the shadows. The Holy Grail War, a brutal battle royale, pits seven mages, known as Masters, against each other. Each Master summons a formidable warrior from various eras as their Servant, all vying for the ultimate prize: the Holy Grail, a wish-granting artifact. Emiya Shirou, an ordinary high school student driven by an unwavering sense of justice, finds himself unwillingly pulled into this deadly conflict. One evening, Shirou witnesses a fierce battle between Servants. The clang of steel and the crackle of magic fill the air as they clash. Mortally wounded in the chaos, Shirou is saved by the enigmatic Tohsaka Rin and her Servant Archer. In a desperate attempt to protect himself, Shirou accidentally summons his own Servant, Saber—a noble and beautiful knight with a mysterious past. As Shirou and Saber navigate the dangerous Holy Grail War, they form alliances and face numerous adversaries, each with their own ambitions and secrets. The bond between Master and Servant deepens as they confront perilous challenges and uncover hidden truths.