At the bottom of the sea, a Japanese diver hits a shell with his hammer and a large fish comes over to see what's going on. But the fish is getting very close, and the diver is forced to repel it with his hand. The fish does not flinch and approaches again. Finally he gets what he wants and swallows the shell. This is a Kobudai fish (Semicossyphus reticulatus), which inhabits rocky reef areas around the Korean Peninsula, China, Japan and the Ogasawara Islands. Diver Hiroyuki Arakawa and the fish named Yoriko, they have known each other for 25 years.