While worries about an ongoing US-China trade spat lingered, a rise by US stock futures following Friday's sharp drop on Wall Street helped soothe sentiment for now.
The Nikkei ended the day up 0.5 percent at 21,678.26, after losing 0.36 percent on Friday.
There were 160 advancers on the Nikkei index against 58 decliners.
The volume of shares traded on the Tokyo Stock Exchange's main board was 1.26 billion, compared with the average of 1.38 billion yen in the past 30 days.
The Topix rose 0.38 percent to 1,725.88, with 24 of its 33 subsectors rising.
Subsectors of defensive shares, consisting of companies that derive a significant portion of their earnings from the domestic market, performed well.
The gainers were led by food, fish and forestry, paper and pulp and pharmaceuticals. Oil and coal products and mining, on the other hand, underperformed.