Asian shares were mixed Thursday, AP reported. Japan's benchmark Nikkei 225 index surged as much as 2 percent to its highest in more than a quarter century before giving up gains and falling 0.3 percent to 22,847.17. South Korea's Kospi lost 0.5 percent to 2,540.80. Hong Kong's Hang Seng added 0.6 percent to 29,073.81 and the Shanghai Composite in mainland China was edged up 0.1 percent to 3,418.53. Australia's S&P/ASX 200 climbed 0.6 percent to 6,049.40. Southeast Asian indexes were mostly lower. The dollar retreated to 113.61 yen from 113.88 yen in late trading Wednesday. The euro strengthened to $1.1606 from $1.1595. Oil futures rebounded. Benchmark U.S. crude rose 3 cents to $56.83 a barrel on the New York Mercantile Exchange. The contract fell 39 cents to settle at $56.81 a barrel Wednesday. Brent crude, used to price international oils, rose 6 cents to $63.55 a barrel in London.