Tokyo's key Nikkei index opened flat on Friday in cautious trade after Wall Street rallies, as investors weighed global inflation and recession risks.

The benchmark Nikkei 225 index was up 0.04 percent, or 11.14 points, at 26,182.39 in early trade after floating between positive and negative territory, while the broader Topix index was down 0.22 percent, or 4.05 points, at 1,847.69.