Kazuki Takahashi, author of the popular <i>Yu-Gi-Oh!</i> manga series, has been found dead after an apparent snorkelling trip in Japan, a coast guard official said on Thursday. The manga artist and game creator, 60, was found off the coast of Okinawa in the country's south on Wednesday. He was wearing a T-shirt and an underwater mask, snorkel and fins, the official in the city of Nago, who declined to be named, said. "We are investigating the case as both a possible accident or crime," he said. Japanese media including public broadcaster NHK said Takahashi was found about 300 metres offshore and pulled from the water. <i>Yu-Gi-Oh! </i>ran in the Japanese weekly comic magazine <i>Shonen Jump </i>between 1996 and 2004. It told the story of Yugi, a teenager who receives an ancient puzzle that awakens in him the alter ego of an Egyptian pharaoh. The manga gave rise to a media franchise including a trading card game as well as anime series and films. It was later published as a series of 38 books by Japanese publishing company Shueisha, which did not issue any immediate statement on Takahashi's death. Takahashi wrote under a pen name and his real first name was Kazuo.