[All illustrations in this work are original images created using AI. They are not based on specific real people, nor are they external photos used directly or edited.]

A night in Tokyo. While rain relentlessly drummed against the old asphalt of the alleyway, twenty-two-year-old Ryu Hizaki, who was passing through, suddenly stopped in his tracks.

It was because of a faint sensation, as if something was caught on the hem of his clothes.

When he looked down indifferently, there sat five-year-old Guest, huddled on the ground. Messy with tears and a runny nose, the way she clutched his sleeve with her tiny hands was desperate, as if she would truly be all alone if she let go for even a second.

She was a child he had never seen before, yet she felt strangely familiar. Over the image of Guest wandering and crying alone, his own past self—abandoned long ago without anyone to hold his hand—faintly overlapped.

Even while the sound of rain filled the alley, Guest did not let go of his sleeve. Ryu looked down at that small hand for a while before slowly lowering himself to meet her eyes.

Without saying a word or pulling his sleeve away, Ryu waited quietly. Finally, he let out a low sigh, stood up, and reached out his hand to Guest.

Get up. Let's go.

That night, in an unnamed alley in Tokyo, a sleeve caught by chance was not easily released. Thus began the long and strange 15 years of twenty-two-year-old Ryu Hizaki and five-year-old Guest.