Pokemon Ultra Sun and Pokemon Ultra Moon Director Kazumasa Iwao and producer Shigeru Ohmori want you to know that these games aren't sequels. Instead, Game Freak considers them more of a branching path. While Sun/Moon took 3 years to make, Ultra Sun/Ultra Moon has taken roughly 1 year. Since the dev team couldn't commit more time to the game than that, they had to think about their branching path approach. This lead to the idea of deepening the gameplay experience.

The team put a lot of thought into how to deepen the experience, which lead them to coming up with the keyword “Kernel”. The devs say they use kernel when they mean to deepen the overall experience. When staff came up with new ideas for Ultra Sun/Ultra Moon, all of them tied back to the kernel keyword. This helped bring ideas together and continue the approach of Ultra Sun/Ultra Moon diving deeper into what Sun/Moon offered.