Boosted by a weakening yen, Japan's Nikkei 225 gained 2.1%, leading a rally among Asian-Pacific markets Thursday. Asian investors applauded comments favorable to economic stimulus from Janet Yellen, vice chairman of the Federal Reserve. Hong Kong's Hang Seng Index rose 0.8%. Australia's S&P/ASX 200 gained 0.7%. China's Shanghai Composite added 0.6%. South Korea's Kospi edged up 0.2%. India's Sensex was up 1%.