Kazuki Takahashi, the Japanese manga artist credited with bringing international fame to the Yu-Gi-Oh trading-card game and comic-book series, has been found dead at the age of 60. The Japanese Coast Guard confirmed his death, according to public broadcaster NHK, which said his body was found floating Wednesday off the coast of Nago in Okinawa Prefecture. He was reportedly found in snorkeling gear. Authorities were able to identify the body after a car-rental company got in touch with police to say they had been unable to reach Takahashi. An investigation is underway to determine his cause of death. Takahashi shot to fame in the late 1990s for his comic-book series, which focuses on a boy who uses a gaming alter-ago to battle his enemies. The series inspired an entire franchise, with a trading-card game and multiple videogames, in addition to several wildly popular spinoffs.