The company—known today as Seven & i Holdings Co.—initially was the Japanese licensee of the 7-Eleven brand. After rapid growth, it eventually took control of the U.S. company that owned the 7-Eleven business.

Under Mr. Ito and a lieutenant who led the convenience-store business, Toshifumi Suzuki, the Japanese “combini” became a phenomenon on its own, different from the traditional American convenience store.

Some 21,000 Seven-Eleven stores in Japan—where the number 7 is spelled out in the name—sell a variety of ready-to-eat foods such as rice balls and sandwiches. They offer services such as bill paying and banking as well as the kind of odds and ends someone might need at 3 a.m. like a stapler or a fresh undershirt.

Mr. Ito wrote that he wasn’t a fan of English words like “shareholder” and “stakeholder” sometimes used by Japanese businesspeople trying to sound enlightened. “There’s no need to get befuddled by this flood of foreign words,” he said. “Business only exists when you have customers.”

Mr. Ito was born in Tokyo on April 30, 1924, to a merchant family. In an autobiography published in the Nikkei newspaper in 2003, he said he learned the business from watching his mother run the family grocery, calling her a model merchant.

His other mentor, he said, was Yuzuru, his half-brother from his mother’s first marriage who came to live with the family. He recalled going with Yuzuru to see American movies starring the likes of Clark Gable and James Cagney before World War II broke out.

By 1946, Mr. Ito’s parents were divorced, he had graduated from a commercial college and the war was over. Mr. Ito went to work at Yuzuru’s store, called Yokado, in front of a Chinese noodle shop in a modest area of Tokyo.

In his autobiography, he recalled those early days when Yuzuru and his family as well as shop employees lived together under the same roof. His wife, Nobuko, the daughter of a clothing-store owner in Tokyo, kept the large brood fed and visited Mr. Ito in the hospital every day for 100 days in 1958 when his arms and legs were broken in a car accident.

Mr. Ito took over the business after Yuzuru died. In 1961, he made his first trip to the U.S., visiting Dayton, Ohio, and he recalled being struck at how commerce was already shifting from the center of the city to big supermarkets and shopping centers on the outskirts.

It was the spark of insight behind the chain of Japanese superstores that Mr. Ito would later name after himself: Ito-Yokado. Around the same time, a brother and sister from the Okada family, also having visited the U.S., built the chain then known as Jusco, now called Aeon Co., Ito-Yokado’s biggest rival.

For Ito-Yokado, convenience stores seemed like a risky gamble. They needed small quantities of many items, different from the big Ito-Yokado stores. Still, the company decided to plunge into the business in 1974.

Mr. Ito had a long friendship with management guru Peter Drucker. In a 2018 memoir, he recalled a speech Mr. Drucker made to Ito-Yokado employees describing the convenience-store business as a great social revolution because small shops could be on the leading edge of retail trends. Seven-Eleven Japan was a pioneer in using technology to get hot-selling items on the shelves quickly.

Mr. Ito’s second son, Junro, earned an M.B.A. at Claremont Graduate University in California at the school now known as the Peter F. Drucker and Masatoshi Ito Graduate School of Management.

When the parent of 7-Eleven stores in the U.S., Southland Corp., was ailing in the late 1980s, it turned to Mr. Ito. He decided to buy majority control of the company as part of a bankruptcy proceeding, saying he prayed it wouldn’t blow up in his face.

Instead, scandal hit from another direction. Top officials of Ito-Yokado were arrested in 1992 and charged with paying off racketeers known as sokaiya who extort money by threatening to disclose unfavorable information about a company. Mr. Ito stepped down as president.

The present-day structure of Seven & i Holdings was created in 2005, and the holding company controls the global 7-Eleven business. At his death, Mr. Ito held the title of honorary chairman.

He is survived by his eldest son, Yasuhisa; a daughter, Hisako; and his son Junro, who is a top executive at Seven & i Holdings.

Write to Chieko Tsuneoka at chieko.Tsuneoka@wsj.com