An honest fisherman steps in to protect a sea turtle being tormented by bullies on the beach, and his kindness earns him an invitation to a castle beneath the sea. This early fantasy film adapts a famous Japanese folk tale and survives as a pink-tinted print. It was long credited to Seitaro Kitayama's 1918 Nikkatsu production, but stills from that version later turned up in a magazine and do not match this film, so its true origin remains uncertain.