The head of 7-Eleven convenience stores in Japan survived an attempt by his boss to remove him and emerged as president at Seven & I Holdings Co. His next hurdles: turn around weaker units and navigate a leadership transition at the country's largest retailer.

Ryuichi Isaka's promotion Tuesday ended weeks of boardroom drama that resulted in the resignation of Chairman and Chief Executive Officer Toshifumi Suzuki. Activist investor Dan Loeb intervened in a letter dated March 27 — first reported by Bloomberg News — saying Isaka should instead be rewarded for Seven-Eleven Japan Co.'s strong results.

The controversy has cast an international spotlight on Seven & I and sparked discussions of Japan's corporate governance, a pillar of Prime Minister Shinzo Abe's efforts to invigorate the nation's economy.