File photo: Agencies

Tokyo's key Nikkei index opened slightly higher on Thursday as investors took heart from rallies on Wall Street but trade was subdued with a lack of fresh market-moving events.

The benchmark Nikkei 225 index edged up 0.30 percent or 66.48 points to 22,505.13 in early trade, while the broader Topix index was flat -- down just 0.07 points at 1,557.16.