Enoshima Prism

Shuta, Saku, and Michiru share a tender moment on a hilltop as youngsters, climbing together to catch sight of a rainbow. The image becomes a quiet symbol of their lifelong bond, echoing through the years as a touchstone they return to in memory. This early scene hints at how small moments shape future choices.

Michiru decides to study in England and entrusts Shuta with a sealed letter to pass to Saku on her departure date. The plans are kept secret from others, introducing a quiet tension about the trio's future. The departure date is December 21, 2010.

Shuta borrows Saku's bike to reach a basketball game, but Saku dies while sprinting toward the station to see Michiru off. The tragedy weighs heavily on Shuta, planting guilt and a sense of irrevocable loss. The event marks a turning point that drives a wedge between the friends.

After Saku's death, Shuta and Michiru gradually lose touch as time moves on. Their once-close bond fades into the background, replaced by distance and unspoken what-ifs. The trio's future seems to diverge as memories drift apart.

Two years later, Shuta attends Saku's memorial on December 20, 2012 and encounters a mysterious watch that appears to rewind events. The device hints at the possibility of bending time and reliving moments once more. The encounter plants the seeds for a dangerous exploration of memory and fate.

Shuta activates the watch and is drawn back to the morning of December 20, 2010. He returns to a school where Professor Matsudo recalls prisms in a lab window that create a rainbow-like effect. The loop reveals a hidden, time-woven layer to the town’s reality.

A basketball teammate hurls a ball at Shuta, triggering another sudden slip back to the present. The incident reinforces the fragility of the past and the reality of returning to a timeline not fully under his control. Shuta navigates these loops with mounting caution.

In a third loop, Shuta is drawn to a shamanistic ritual behind a classroom door, where the spirit of Kyoko appears. The encounter unsettles the timeline and foreshadows deeper truths about time’s rules. Kyoko becomes a guiding, enigmatic presence in his journey.

A hypnotic session with a science teacher reveals Kyoko is a time prisoner visible only to time-travelers. She teaches a cautious method—the Jack Fin technique—to change as little as possible. The revelation imposes a strict rule on any future meddling with time.

That night, Shuta tries to coax Michiru into confessing her England plans, but she remains resolute. Midnight arrives and the timeline shifts, risking erasure if meddling continues. To save Saku and others, Shuta makes a heartbreaking sacrifice and Kyoko passes the watch to him.

The timeline returns to the 2010 version of Shuta, arriving on the basketball court without the watch. He proceeds within the altered present, unaware of the deeper changes brewing in the past. This reset prepares the stage for revelations that will come in the 2012 loop.

In the 2012 loop, Shuta confirms that Michiru's letter truly reveals her feelings and that she loves him. He and Saku ride toward the station, determined to connect with Michiru, believing love might still bridge the timelines. He realizes he could have saved Saku all along, deepening the emotional cost of the time-travel experiment.

After the climactic events, the memories of Shuta fade from everyone’s minds—except for Kyoko, who remains the constant thread. She vows never to forget him, becoming the lone anchor to a story that refuses to be fully erased. The town moves on, carrying only the faintest glimmer of what happened.

Years later, on a sunlit beach, Shuta appears with a quartz prism in hand. Saku and Michiru walk in the distance, and Michiru recognizes the prism as a token of their shared memory. Shuta gifts the prism to Michiru before parting as strangers again, with Kyoko as the sole keeper of his memory.