The Summoning and the Curse of "Return by Death"
Exiting a Tokyo convenience store in his tracksuit, ordinary NEET teenager Subaru Natsuki blinks and finds himself standing in the bustling fantasy capital of Lugnica. Expecting typical overpowered isekai cheats, Subaru quickly discovers he has no sacred sword, no elemental affinity, and no physical buffs.
Cornered by street thugs, Subaru is saved by a compassionate silver-haired half-elf introducing herself as "Satella" (accompanied by her cat familiar, Puck). Grateful, Subaru helps her search for her stolen royal insignia. Tracking the thief Felt to a shady loot house, Subaru enters—only to have his intestines sliced open in the dark by the psychopathic assassin Elsa Granhiert.
As his vision fades to black in a pool of blood, Subaru suddenly gasps for air back at the fruit vendor's stall hours earlier! After dying repeatedly in grotesque ways, Subaru realizes the horrific truth: he possesses Return by Death. When he dies, time rewinds to an invisible checkpoint. Crucially, a shadowy, suffocating curse prevents him from ever speaking of this power to anyone—attempting to confess causes an ethereal hand to crush his heart or murder those around him.
Roswaal's Mansion and the Twin Maids Rem and Ram
With help from the Sword Saint Reinhard van Astrea, Subaru defeats Elsa and learns the half-elf's true name is Emilia, a candidate for the Lugnica throne. Brought to the lavish estate of Margrave Roswaal L. Mathers, Subaru becomes a butler, living alongside the twin demon maids Rem and Ram, as well as the spirit librarian Beatrice.
Subaru dies repeatedly from mysterious curses and is even brutally murdered by a suspicious Rem. Through sheer empathy and courage, Subaru breaks the loop by fighting off cursed mabeasts in the forest and risking his life to shield Rem, earning her unconditional devotion and eternal love.
The Witch Cult, Despair, and "From Zero"
When the royal selection formally commences in the capital, Subaru's pride and possessive attitude embarrass Emilia, who cuts ties with him. Left behind for healing under Crusch Karsten, Subaru learns that Emilia's domain is being attacked by the sinister Witch Cult.
Returning to the mansion, Subaru encounters pure nightmares: the psychotic Archbishop of Sloth, Betelgeuse Romanee-Conti, who tortures Rem to death with invisible hands; the fog beast White Whale erasing people's very existence from human memory; and Puck turning into the colossal beast of the end to freeze Subaru to death.
Broken by continuous trauma, Subaru collapses into suicidal despair and begs Rem to abandon everything and run away with him. In the monumental masterpiece Episode 18 ("From Zero"), Rem refuses to let Subaru give up on himself. She confesses her boundless love, reaffirming that Subaru is her hero: "Starting from right here, from zero, let's start over!"
Reborn with clarity, Subaru unites the rival royal camps of Crusch Karsten and Anastasia Hoshin. Spearheaded by the legendary veteran swordsman Wilhelm van Astrea, they slay the White Whale, avenge Wilhelm's wife Theresia, and dismantle Betelgeuse's fingers, allowing Subaru to save Emilia and reconcile tearfully.
The Sanctuary and the Witch of Greed
Season 2 brings another gut punch: Archbishops of Gluttony and Greed attack the returning convoy, eating Rem's name and memories, leaving her comatose and forgotten by everyone except Subaru.
Traveling to The Sanctuary, Subaru faces the tomb of Echidna, the Witch of Greed, entering her dream tea parties to take the psychological trials of the past, present, and future. Discovering Roswaal possesses an apocalyptic Gospel and deliberately orchestrated every disaster to force Subaru into becoming a ruthless savior, Subaru refuses to sacrifice anyone. With help from Otto Suwen, Garfiel Tinsel, and Beatrice (whom Subaru frees from her 400-year solitude in the forbidden library), Subaru defeats the Great Rabbit and is officially knighted by Emilia as her true knight.