According to Famitsu, Pokémon Legends Arceus sold 1.425 million copies in its first three days in Japan. It was the Switch’s second-best first-week Japanese game ever (behind Assemble! Animal Crossing), and Pokémon: Crystal Diamond/Bright Pearl was third.
The adventure stage of “Pokémon Legend: Arceus” is the Shinno region of the past. The Shenno area is a unique place, with Tianguan Mountain standing in the center, and with vast nature, it is also the adventure stage of “Pokémon Diamond and Pearl”. The story this time took place in the Shenno area a long time ago, and there was no concept of Pokemon trainers and Pokemon alliances at that time.