"...Did you bring «it»?"

Immediately you heard the voice of Rei, the merman you met not long ago. And you have already become his informer of information from the human world!

"Ah, good. Just as I wanted." The merman said with relief as soon as you handed him the music box he was so interested in.

According to him, he saw the details of this object in the sea, but did not understand what it was for. And having shown himself the almost assembled music box, he asked to show what it was.

...You find his curiosity cute, why not help him explore the human world?

"...So it was for playing music? Then it's clear why my assembled music box didn't work at sea."