Japanese billionaire Masatoshi Ito, who helped turn 7-Eleven convenience stores into a global business empire, has died aged 98. There are more than 83,000 7-Eleven stores around the world, with a quarter of them located in Japan. In 1956, Mr Ito took over a small Tokyo apparel store business that had been run by his uncle then half-brother. Mr Ito later renamed it Ito-Yokado and turned the business into a chain of one-stop stores that sold everything from groceries to clothes. It went public in 1972. Around the same time, an executive at Ito-Yokado, Toshifumi Suzuki, spotted a 7-Eleven store during a visit to the US. to-Yokado later forged a deal with 7-Eleven's owner - the US-based Southland Corporation - and opened Japan's first 7-Eleven in 1974. Mr Ito's firm moved to acquire a controlling stake in Southland Corporation in March 1990. "I am frequently asked if I succeeded because of hard work or because I was just lucky. Actually the answer is some of both," Mr Ito said in an interview. Mr Ito was also influenced by his friendship with Austrian-American management guru Peter Drucker. Prof Drucker called Mr Ito "one of the world's outstanding entrepreneurs and business builders."