It was up 1.82 percent over the week.
"Expectations that US-China trade friction would ease spread on the markets... Investors bought back Japanese shares following gains on Wall Street," Okasan Online Securities said in a note. A weaker yen against the dollar is also supporting Japanese shares, analysts said.
The dollar fetched 109.36 yen in Asian trade, against 109.19 yen in New York late Thursday. US stocks suddenly jumped higher after The Wall Street Journal reported Treasury Secretary Steven Mnuchin had proposed lifting some or all tariffs on China as a way to reassure markets and bolster the odds of a bigger trade deal. In individual Tokyo trade, electronics firms were higher, with Sharp soaring 9.03 percent to 1,207 yen and Panasonic rising 1.29 percent to 1,058.5 yen.
However, precision motor maker Nidec fell 1.12 percent to 12,255 yen after it said its net profit for the year to March would be 14 percent lower than the previous year.
Hitachi edged down 0.20 percent to 3,475 yen after it froze construction of a nuclear power station in Britain, booking a cost of 300 billion yen ($2.8 billion).