Doctor Hayshida is a scientist working on gene mutations in the 1984 Godzilla film, The Return of Godzilla
Doctor Hayashida lost his parents in the original 1954 Godzilla raid on Tokyo. This led him to begin his career studying Godzilla out of a need for vengeance for them. He later realized that Godzilla was nature's reminder of what man has done, and is capable of doing. It was this philosophy that led him to seek a non-lethal way to remove Godzilla from Japan. He is first brought into the film when Goro Maki is told by his editor to seek him out. Doctor Hayashida believes Godzilla to be indestructible. Hayashida knows a great deal about Godzilla's physiology, being able to determine brain function, and size from a few pictures. After figuring out that bird calls attract Godzilla, he builds a machine to simulate bird calls, an instrument that will become instrumental in bringing Godzilla down. After testing the machine, he is picked up by the military and it is put in an amplifier. After the device is turned on, Godzilla is lured into Mount Mihara, leaving Hayashida successful.