Underwater photographer Ikuo Nakamura has been photographing the seas around Japan for over 40 years. One of his life's goals has been to capture on camera one particular giant fish -- the Asian sheepshead wrasse. This over one meter in length fish with large protrusions commands the sea with its imposing dignity. One particular fish called Benkei, after the medieval monk warrior. For years Benkei was the authority of the waters, but recently his number two has been lying in wait to take over. The Monster of the Sea captures the power game between these monster fish in the beautiful arena of the Japan Sea.