The next season of the anime Pokémon is a global adventure that will take place in all regions of the main Pokémon games. However, Ash Ketchum and his new partner will be based in the Kanto area, as new details about the series revealed that Ash would be working with a new Pokémon professor in Vermilion City.
Ash Ketchum recently won the Alola League, which suggests that he would retire as a protagonist of the series or that the anime Pokémon would be revived. It turns out that the next season of the anime Pokémon will change format and will include adventures in each region. Ash will focus on the Pokemon fights and his new partner (subtly called Go) will attempt to catch all Pokémon.
The adventures of Ash and Go will take place in Vermilion City, where they will operate from the Sakuragi Lab building. According to Serebii, Ash will be dealing with a new Pokémon teacher, Professor Sakuragi, and his lab will be the focus of next season. Sakuragi has a daughter named Koharu (see below) who owns a Yamper. Koharu is said to be a childhood friend of Go, suggesting that both are from the Kanto region.
It may seem odd to use a new teacher in the Kanto area because Professor Oak has been part of the Pokémon anime since the first episode. However, the change is probably due to the circumstances of real life. The former actor of Professor Oak in Japan, Unsho Ishizuka, died in 2018. Kenyu Horiuchi spoke for Professor Oak’s role, but program staff may wish to respect Ishizuka’s death. It seems that they can gradually eliminate Professor Oak from the program, at least for the moment.
It is possible that Ash and Go is based in the Kanto region because of technology that would allow them to travel long distances. This would also explain the laboratory environment. The fans will not have much time to discover, because next season the anime Pokémon will debut in Japan on November 17, 2019.