https://www.gamespot.com/articles/nintendo-switch-hits-15m-sales-in-japan-a-lot-fast/1100-6453107/

According to newly released figures, the Nintendo Switch has reached 1.5 million sales in Nintendo's home country of Japan since launch in March. That's a big number, and to put it in context, it's significantly better than the start for the PlayStation 4 in 2013.

The Switch reached 1.5 million sales after 26 weeks in Japan. By comparison, after the PS4's first 26 weeks on sale in Japan, the console sold around 665,000 units. It took the PS4 69 weeks to reach 1.5 million units sold in Japan.