Almost two years ago, Nissan Motor led all Japanese carmakers in profits. It was faster than its peers in moving production overseas to counter the stronger yen, expanding into emerging markets, and recovering from the tsunami and other natural disasters in 2011. Today it's recovering from production delays. Emerging markets are slowing, and it's missing out on the profit boon from a weaker yen enjoyed by most Japanese exporters. The result: Nissan today has become Japan's least profitable carmaker. The company's net income rose 57%, to 84.3 billion yen ($825 million), in the three months ended Dec 31, but that net was 3.3% of revenue, the lowest margin among Japanese carmakers last quarter.