Natsuki Subaru is summoned to a parallel world on his way home from the convenience store. He's entranced at first by the fantasy world suddenly stretching before his eyes, but the cute girl he believes summoned him is nowhere to be found, and soon enough he's utterly lost. Then a gang of punks surrounds him, but he quickly learns that he doesn't have any of the powers that he thought all people transported to a parellel world should have. Just when he's about to be beaten senseless, a girl appears...

Upon returning to Roswaal’s mansion, Subaru is greeted by an unbelievable sight and wails that this was not what he wanted to happen. Stricken with despair, everything before Subaru starts to go white as, finally, he hears a voice: “You were too late.”

Subaru laments that he could not do anything or save anyone, and has no options left. Exhausted, he suddenly takes off running at full speed as if he’s made a decision…

Emilia is hurriedly ushered to the capital along with the villagers under the orders of a mysterious benefactor while escorted by a rag-tag group of individuals from various and opposing factions. She has but one question on her mind: who could this man be and why would he go so far? Meanwhile, Subaru and Julius face off against the Archbishop of Sin Betelgeuse for the ultimate time. Unfortunately, he is very persistent even beyond death, belying his nature of Sloth. Subaru is relentlessly chased while he catches up to Emilia to save her one last time and answer her question.