What was the original working name of the Pokémon project?

The original working name of the Pokémon project was Capsule Monsters.

Satoshi Tajiri and the Game Freak team initially used the name while developing their creature-collecting game for Nintendo’s Game Boy. The concept involved storing creatures in capsules and exchanging them between players through the Game Link Cable.

The name was later shortened informally to Capumon. However, Capsule Monsters could not be trademarked, so the project was renamed Pocket Monsters. The Japanese game title became Pocket Monsters Red and Green, while the internationally recognized abbreviation became Pokémon.

The capsule idea also reflected influences from Japanese monster media, including Ultraseven, whose creatures could be stored in capsules. This history explains why Poké Balls are central to the series even though the franchise’s final name does not directly mention capsules.