TV-Series
Description
Subaru Hoshikawa is a fifth-grade student whose father, an astronaut, disappeared in a space station accident three years prior. This tragedy plunged him into a period of depression and social withdrawal, causing him to neglect school and become isolated. He often sought solace at an observation platform, a place that made him feel closer to his father.

His life transformed when he encountered an extraterrestrial EM wave life form from the destroyed planet AM, known as War-Rock. This meeting happened after Subaru used a special pair of goggles called a Visualizer, left to him by his father, which allowed him to perceive the EM Wave World. War-Rock, a fugitive who had stolen the Andromeda Key, claimed to know something about Subaru's missing parent. The two formed a partnership and gained the ability to perform an Electromagnetic Wave Change, merging to become an EM Wave Human known as Rockman.

Initially reluctant to engage in violence and fearful of being hurt, Subaru was driven by a desire to protect his friends from threats in the EM Wave World. He began to embrace his role as Rockman, a journey that facilitated his gradual emotional opening and led him to interact more with classmates like Luna Shirogane. He formed a BrotherBand with others, and his primary motivation evolved into a commitment to justice and safeguarding Earth.

A few months later, Subaru and War-Rock became involved with an ancient artifact known as the Sword of Berserk, an OOPArt from the lost civilization of Mu. War-Rock swallowed the artifact, granting Rockman a new transformation called Thunder Berserk. They were tasked by Doctor Orihime to find other OOPArts before antagonists like Hyde, Gori Monjirō, and the solitary soldier Burai could acquire them.

Subaru traveled the world searching for these artifacts, frequently struggling against adversaries and working to master his new form. He discovered Doctor Orihime's true goal was to use the OOPArts to resurrect the ancient entity Le Mu. During the final confrontation on the revived Mu continent, Subaru demonstrated significant self-sacrifice by having War-Rock terminate their fusion to spare him from an attack, which led to the extraction of the OOPArt. The three OOPArts resonated with him, allowing Rockman to access new transformations: Green Shinobi, Fire Dinosaur, and the powerful Tribe King form to oppose Le Mu's resurrection.

In the climax, after Le Mu was resurrected and attempted to cross over to Earth, Subaru escaped alongside allies like Harp Note, Yeti Blizzard, and Phantom Black. The soldier Burai, who shared the mission of preventing Mu's return, sacrificed himself to hold off Le Mu so Rockman could destroy the portal using the Czar Delta Breaker, sealing the continent and its threat away.

Following these events, Subaru's life returned to peace. He attended a concert with his mother, friends, and allies, where various FM-ians and their hosts from his adventures were also present, indicating a reconciliation and coexistence.

Subaru is genial but was initially lonely and burdened by grief. Through his experiences and bonds, particularly with War-Rock, he developed into a more confident and proactive individual, though he remains scared of ghosts and has an aptitude for machinery and astronomy. His relationship with War-Rock evolved from a partnership of convenience into a deep, mutual care for each other and the planet they protect.