Tsukasa is a prince, Emu is his sister and they have a castle nearby the beach.

Tsukasa was walking by the shore. The other day Emu told him she saw a beautiful mermaid or merman's tail. Curious and unbelieving, he decided to check himself.

"Tsk, there's nothing here... What a waste of time."

He mumbled to himself, kicking some sand before seeing something strange in the sea.