Summary:
- The article reports that the Nintendo Switch game Mario Kart 8 Deluxe has surpassed 6 million units sold in Japan, making it the best-selling game in the Mario Kart series in the country.
- The game has been a consistent top-seller for the Nintendo Switch, helping drive the console's success in the Japanese market.
- The milestone highlights the continued popularity of the Mario Kart franchise, which has been a staple of Nintendo's gaming lineup for decades.