Professor Morimori is one of the three senior scientists who staff the Photon Power Laboratory in the Mazinkaiser anime, working alongside his colleagues Professor Sewashi and Professor Nossori. The trio, commonly referred to as the three doctors, is among the most experienced research teams at the facility. All three were originally apprentices of Juzo Kabuto, the creator of the Mazinger robots, and after his passing they continued their scientific work under the direction of Professor Yumi. Among the three, Morimori has the stoutest build and is easily recognized by his portly figure, balding head, and dark beard.

As a researcher, Morimori is a brilliant man in his late fifties who tends to find solutions where others see none. His practical knowledge and engineering skill make him a dependable member of the laboratory staff. In the Mazinkaiser series, the three doctors are responsible for maintaining and servicing the laboratory's robots, including Mazinkaiser itself and the Venus A unit. The three doctors developed the Venus A together, modeling its appearance on Sayaka Yumi. Morimori also has a long personal connection to the Kabuto family, having known Koji Kabuto since the pilot was a small child. He holds genuine affection for Koji and treats the younger members of the laboratory with warmth and protectiveness. He is notably eager in his willingness to help, and that eagerness shapes his actions throughout the story.

In the main Mazinkaiser OVA, Morimori functions as a supporting figure, contributing to the defense of the laboratory through his technical duties and assisting the pilots from behind the scenes. His role becomes far more prominent in the sequel OVA that follows the main series. He is the only one of the three doctors to accompany Koji on an overseas trip to Paris, a journey meant to combine an inspection tour with a period of rest for the pilot. When the Mycenean Empire begins its invasion of Earth, Morimori quickly grasps the seriousness of the situation and works to bring the group home. During the return flight, their aircraft comes under attack by the empire's warrior beasts over the Arctic, and Morimori is among the survivors of the assault. The group eventually reaches a Russian military base, where he explains the threat of the Mycenean Empire to the soldiers stationed there, drawing on knowledge he gained from the diary left behind by his old master Juzo Kabuto. While studying the world map displayed on the base's monitors, he realizes that the facility holds nuclear missiles capable of being launched, and he quietly forms a plan to use them as a final resort.

When Mycenean forces attack the base, Morimori insists that Koji and Sayaka escape to Japan without him. He then launches the nuclear missiles in a suicidal attack that destroys the enemy army and the base along with it. Before his death, he entrusts Koji with a final message for his longtime colleagues Sewashi and Nossori. His sacrifice is driven by loyalty to his friends and dedication to the cause, and it represents the fullest expression of his character, transforming a background scientist into a decisive figure whose final act saves the survivors. Morimori's notable strengths lie in his scientific expertise in robotics and mechanical engineering, his quick strategic thinking, and his willingness to act on difficult conclusions when the safety of others is at stake.