21 years ago, a baby arrived on earth inside of a peach. Today, five warriors based on the legend of Momotaro fight enemies that are inhabiting humans, invisible to the naked eye. Together they fight to take back gears based on previous Super Sentai.

In 1945, Dr. Ryuichiro Koga designed Metalder as a top-secret weapon for the Japanese Imperial Army for use in the Pacific War, modeling it after his late son, Second Sub-lieutenant Tatsuo Koga. However, the pacifistic Dr. Koga puts him to sleep in the Silver Carcass base and left for America to work for NASA. During the 42 years, Dr. Koga's former colleague Major Muraki became the evil God Neros and sends out his massive armies to kill Dr. Koga, who learned of their organization and returned to Japan to activate Metalder. Koga desperately tries to activate his android creation, who he named Ryusei Tsurugi, but the android is unable to understand what to do. In order to give Ryusei a "purpose", Koga runs out of the Silver Carcass base, allowing Neros' troops to kill him. Suddenly seeing his creator die, Ryusei becomes shocked and fueled with rage, evoking the conversion to his 'true' form, the android known as Metalder.

At a high school in Tokyo, several of the female students have been moon-lighting as prostitutes. A teacher catches onto this fact and goes about putting an end to it. Things go awry when he discovers he turns into a sex demon with tentacles whenever he gets aroused or angry.

The intercom rings. When Tanaka Yuka responds, she sees a woman she doesn't recognize. The woman says she wants to pay back the money she'd borrowed for taxi fare to Yuka's husband Shinji, who insists he lent her the money at a bar. Yuka, who is suspicious of the differing stories between the two, looks at her husband's phone that night. There she finds exchanges of extramarital affairs with five women. Shocked, Yuka works together with Kaito in order to identify and eliminate her husband's adulterous partners. Meanwhile Yuka and Kaito gradually become closer, which eventually leads to a physical relationship...

In different parts of Tokyo, four young and seemingly healthy people suddenly die of heart failure at exactly the same moment. Reporter Kazuyuki Asakawa decides to investigate the deaths, and discovers that the four had stayed at a rural inn together just a week earlier. At the inn, he comes across a strange video that ends with a message saying that anyone who watches it will die exactly seven days later. Now the clock is ticking for Asakawa. Can he break the curse in time?

Around 200 years ago, a meteorite fell in a village in the Tohoku region. There was no immediate damage after the impact, but after some time, the villagers living in the vicinity experienced genetic mutations and a few gained "special powers". An ordinary office worker, Hiroyuki Sano, suddenly exhibits these powers one day

Office worker Mayu Sakashita has been manipulated by the man she believed was her boyfriend into joining a pyramid scheme, leaving her burdened with debts to a loan shark. One day, Kinji, the head of the underground lending operation, gives her an unusual assignment: track down Chihiro, a woman who disappeared after borrowing a large sum of money and is said to be hiding while working at an unlicensed escort service. Kinji offers Mayu a deal - if she becomes one of his subordinates and goes undercover, risking her own body to infiltrate the operation, he will wipe out her debt. Desperate and seeing no other way out, Mayu eagerly accepts the offer...

A film version of Super Android Metalder, set between episodes 17 & 18 premiered on July 18, 1987 at the "Toei Manga Matsuri" film festival, where it was shown as part of a quadruple feature alongside Dragon Ball: Sleeping Princess in Devil's Castle, Saint Seiya: The Movie and the film version of Hikari Sentai Maskman.

The referendum whether nuclear power plants should be banned has been held in Japan. People must decide their future.