Today, the aquarium is full of people who come to see the most popular dolphin nDolphin. The bubbly nDolphin perform amazing stunts at the concert hall and receive applause from the crowd. 
But the nDolphin who sigh from exhaustion on the same day every day... Then, a kid who suddenly appeared in front of me handed me something shiny. The startled nDolphin looked into it was a gemstone necklace, and when the nDolphin looked back, the kid was gone! 
Who was the little boy? And, what is that gemstone?