May 2020 is the 39th month that the Nintendo Switch has been available for in Japan. During the latest month, the Switch closed the gap to the 3DS by 341,098 units. In the last 12 months, the Switch has outsold the 3DS by 1.18 million units. The 3DS is currently ahead of the Switch by 1.96 million units.
source: gamezpot.com