This story is divided into three seasons, and there is no single main character.
Season 1: A boy’s story who gets trapped in a time loop. His life becomes exactly like his professor’s life.
Season 2: A boy’s story who builds a time machine and also gets trapped in a loop.
Both storylines are connected to three mysterious necklaces, which are the central objects of the story and hold special powers. These necklaces are crucial to the plot.
Season 3: The connection between the previous two seasons’ stories is revealed and the main villain appears.
The villain’s motives, reasons, and methods are fully explained.
The story shows how the necklaces are involved in the villain’s plan and their importance in the plot.

Core Concept: This anime explores loops, suspense, mystery, manipulation, and psychological tension. The necklaces play a central role in the story’s secrets and guide the characters and plot toward a mind-bending climax.