What was the original development name of the first Pokémon game project?

The original development name of the first Pokémon game project was Capsule Monsters.

Satoshi Tajiri initially proposed the project under that name while developing the concept at Game Freak. The title reflected the idea of storing creatures in capsules and releasing them for adventure and battles. Staff members reportedly shortened the working name to “Capumon.”

The name later changed because “Capsule Monsters” could not be trademarked. The project became Pocket Monsters, which was eventually shortened and stylized internationally as Pokémon. This naming history explains why the Japanese franchise title remains Pocket Monsters even though most global audiences know the shorter brand.

The concept also drew on Tajiri's childhood interest in collecting insects and on the Game Boy link cable's ability to connect players. Those ideas became the foundation of Pokémon's central loop: discover creatures, collect them, train them, and exchange them with other players.