Tateyama, Chiba Prefecture
Banded houndshark, measuring over 1 meter in length, gather at an undersea feeding ground, set up to protect fixed nets. What a compelling scene as we watch hundreds of them swimming around divers. A giant, friendly Asian sheepshead wrasse living near the country's only undersea shrine is also pretty magical.
Ainan-cho, Ehime Prefecture
Japan's seas are the northern limit for the existence of coral reefs. Here, we encounter Japan's largest table coral colony, and myriad fish of both temperate and tropical zones. This is also one of Japan's leading skipjack tuna fishing areas, as the fish come riding on the Kuroshio warm current.
Ishigaki Island, Okinawa Prefecture
Japan's largest lagoon fans out west of Ishigaki Island, and 400 coral species thrive there -- that's half of the planet's total in one spot. We visited in October during manta ray mating season, and observed the courtship of 3 giants swimming as if dancing.
Mikomotojima, Shizuoka Prefecture
Michael plunged into a hammerhead shark habitat. The creature, about 5 meters in length, is found widely around the world, but rarely in groups. We succeeded in filming hundreds of them by diving in a very fast-current area -- like being tossed about in a washing machine.