Tokyo stocks closed flat as investors looked for evidence of increased economic activity in Japan. The Nikkei 225 index rose 0.08 percent, or 21.70 points, to 26,171.25. The Topix index fell 0.05 percent to 1,851.74. Tokyo stocks closed flat, as investors looked for evidence of increased economic activity in Japan following the relaxation of influenza restrictions. The Nikkei 225 index