TOKYO, April 6 (Xinhua) -- Tokyo stocks opened higher Friday as the yen's retreat against the U.S. dollar gave exporters here boost, but gains were limited over market concerns about U.S. initiated trade frictions.

As of 9:15 a.m. local time, the 225-issue Nikkei Stock Average gained 38.24 points, or 0.18 percent, from Thursday to 21,683.66.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, added 1.61 points, or 0.09 percent, at 1,726.22.

Retail, precision instrument and transport equipment-linked issues comprised those that gained the most in the opening minutes after the morning bell.