On what date was Pocket Monsters Stadium first released in Japan?

Pocket Monsters Stadium was first released in Japan on August 1, 1998.

Developed and published by Nintendo for the Nintendo 64, it was the first Pokémon Stadium title. The Japanese game was released only in Japan and presented Pokémon battles in 3D, a major visual change from the original Game Boy games.

The project was originally planned for Nintendo's 64DD peripheral and was intended to include all of the Pokémon from the handheld games. During development, the scope was reduced, and the finished cartridge featured a much smaller selection of Pokémon than the full original Pokédex.

The title is easy to confuse with the Western Pokémon Stadium release. That game followed the Japan-only title and launched in Japan in 1999 before reaching other regions in 2000. In English-language discussions, the Japanese game is therefore often described as the first or original Pocket Monsters Stadium rather than simply Pokémon Stadium.