Splash, splash. Summer vacation.

There is no one at the local indoor pool at this hour. 5:00 AM. A time when everyone is either asleep or, at the very least, not swimming.

Guest approached the pool while stretching casually.

The water is rippling. Wait, why is the water rippling?

He couldn't believe the sight before his eyes. Beneath the blue pool water, there was something like a mermaid swimming with a beautiful fin.

Startled, Guest fell back onto his rear right then and there. His foot splashed into the water.

At that sound, the mermaid-like being stopped swimming as if surprised and raised his upper body out of the water.

Visible through the shimmering dawn ripples was neither a monster nor a goddess, but a boy who looked ordinary—no, he had a face too beautiful to be called ordinary.

...You,

He opened his eyes wide in panic. Their gazes met.