The Nikkei climbed 1.88% to 38,432.98, its highest close since May 13.
The broader Topix rose 1.53% to 2,812.02.
The Manhattan-based Court of International Trade ruled that Trump overstepped his authority by imposing across-the-board duties on imports from nations that sell more to the United States than they buy.
“The news was positive as Trump’s tariff plans are a headwind for the corporate and economic outlook,” said Kentaro Hayashi, senior strategist at Daiwa Securities.
“And the yen weakened on the news, which drove a rally in the auto sector,” he said. The U.S. dollar surged following the court decision, pushing the yen to fall as low as 146.26 against the greenback. A weaker yen boosts the value of overseas revenues. Chip-related shares jumped after Nvidia beat quarterly sales expectations, with Advantest and Tokyo Electron rising 5.35% and 4.25%, respectively.
Cable maker Fujikura, a gauge for AI investments, jumped 5.54%. It lifted the nonferrous metals sector by 5.8%, making it the top performer among the Tokyo Stock Exchange’s 33 industry sub-indexes.
Shares of Toyota Motor rose nearly 4%, helping lift the auto and auto parts sector by 3.39%.
Hino Motors and Nissan Motor jumped nearly 6% each.
On the other hand, toy maker Bandai Namco Holdings fell 2.96% to drag the Nikkei the most.