Tokyo stocks ended 0.52 percent lower in the morning session of Thursday after giving up early gains as investors locked in recent gains. The 225-issue Nikkei Stock Average was down 75.80 points,from Wednesday to 14,386.72. The broader Topix index of all First Section issues on the Tokyo Stock Exchange shed 6.43 points, or 0.55 percent, to 1,157. 90. The decline was led by real estate, paper and pulp, and steel shares while retail shares advanced.