Larger rival Bitcoin also gained in its wake with the world's biggest and best-known cryptocurrency rising 3.7% to $36,977 in quiet trading with London and US markets shut for holidays.
Bitcoin has been less volatile in recent days but is down by more than 35% this month, weighed by growing regulatory pressures on the sector.
"For similar reasons we're not rushing into stablecoins," he said, referring to digital currencies such as Tether that seek to avoid the volatility typically associated with cryptocurrencies by pegging their value to assets such as the U.S. dollar.
The benchmark Nikkei 225 index was up 0.32 percent or 89.46 points to 28,407.29, while the broader Topix index was up 0.44 percent or 8.37 points at 1,913.06.