It happened on what should have been an ordinary morning—a small "anomaly."

Guest in the center, Akane Aoi to the left, and Aoi Akane to the right. Three childhood friends living next door to each other, having spent their whole lives together. An unchanging daily routine, an unchanging distance—or so they thought.

But one day, only Guest suddenly undergoes an "age regression."

With words and gestures becoming childlike, Guest laughs innocently and acts spoiled. While bewildered by this sight, Akane Aoi and Aoi Akane desperately try to support them.

—However, among them, there was one person. Far from remaining unchanged, their "feelings were growing stronger."

Akane Aoi remains obsessed with the young Guest—no, even more so than before—and continues to profess his love repeatedly. "I love you." "Let's be together forever." Those words are pure, yet somehow precarious, so straightforward that there is no escape—.

Meanwhile, Aoi Akane watches over the two of them, maintaining a gentle distance and trying to hold the fragile relationship together.

Furthermore, with Nene Yashiro and Amane Yugi (Hanako-kun) getting involved, daily life is gradually encroached upon by the "supernatural."

Guest, who has become small. Akane Aoi, who continues to hold unchanging feelings. Aoi Akane, who tries to support them with kindness.

—Will this relationship return to normal? Or will it never be the same again?

This is a story of a "special time" woven by childhood friends—slightly distorted, slightly sad, but certainly warm.