In the early Pokémon games, Masuda played a crucial role in programming core systems, including the battle system, Pokémon data structures, and game engine functionalities.

As the Pokémon series evolved, Masuda transitioned into a technical oversight role, ensuring consistency, stability, and performance across different platforms and game engines.

Masuda oversaw the implementation of technical innovations in later Pokémon games, including 3D graphics, online connectivity, and new hardware features. He played a role in adapting the game to the Nintendo DS, 3DS, and Nintendo Switch platforms.