TOKYO -- Takashi Yanase, creator of one of Japan's most beloved cartoon characters, Anpanman, has died of heart failure, his studio said Tuesday. He was 94.

Yanase died at a Tokyo hospital early Sunday, Yanase said in a statement. He had been treated for liver cancer since August.

Anpanman is a superhero with the head made of anpan, or bread filled with red bean paste, a typical snack in Japan. In the cartoon, the round-faced, smiley hero, clad in a red suit and long cape, fights his archrival Baikinman, or a germ man, while rescuing the weak.

The self-sacrificial hero, who even allowed starving people to bite into his head, rose to stardom in Japan in a picture book series that started in 1973, racking up sales totalling 68 million copies over the past 30 years. The Anpanman television cartoon series started in 1988, and has spread across Asia, where is also popular in places like Hong Kong and Taiwan.

The cartoon series, "Let's go! Anpanman," entered the Guinness World Records in 2009 for the largest number of characters at more than 1,700.

A former graphic designer, Yanase debuted as a cartoonist and served as lecturer on a "manga school" quiz show on Japan's NHK television.

"Mr. Yanase was the Anpanman. He embraced us gently and taught us to share," actress Keiko Toda, whose voice was used for Anpanman's character on the TV show, said in a statement. "We've lost a precious guiding post."

Makoto Amano, an official at the publishing agent, said Yanase had briefly retired before the March 2011 earthquake, tsunami and nuclear disasters, but returned to work after learning that an Anpanman theme song was cheering up residents in the disaster-hit region, Kyodo News agency said. On Saturday, he was still discussing ideas with his staff about an upcoming Anpanman film set for release next year, Kyodo said.

Yanase, known for his pacifist messages, also wrote poems and lyrics for children's songs.

"It's October as usual. I'm doing fine, so please feel at ease," he closed his monthly poem greeting published on his website.