Ichirou Hongou serves as the male lead of the story. His background is unusual due to an accident in his childhood when he was hit by a falling spaceship. This event resulted in him receiving a cyborg body, which grants him a specific and peculiar set of abilities.

In terms of personality, Ichirou is defined by his deep and overwhelming infatuation with a girl named Yuuki Kurama. Much of his energy is spent trying to confess his romantic feelings to her, though his efforts are frequently complicated by his own reactions. For example, when he pictures Yuuki without her underwear or sees her naked, he has a tendency to get a nosebleed. This predicament is further highlighted by his accidental possession of a pair of her panties, which he spends several episodes trying to return.

Ichirou's primary motivation is to confess his love to Yuuki and win her affection. His role in the story revolves around this romantic pursuit, which unfolds alongside the main plot of alien attacks. When he finally does confess, Yuuki responds that she loves him, but also loves everyone else, which keeps his goal unfulfilled. His relationships are notably complicated, as three other female characters, Yayoi, Sera, and Zero, harbor romantic feelings for him. His most significant relationship development occurs towards the end of the OVA, where it appears he becomes engaged to Zero due to a galactic rule of questionable authenticity.

His cyborg body grants him the notable ability to transform into a warrior named Cosmo Banchou. This transformation is a parody of characters like Tuxedo Kamen and is triggered in moments of intense sexual desire. Over the course of the story, his development is primarily comedic, as he navigates a love pentagon and the bizarre circumstances of his own abilities, ultimately leading to an unexpected engagement with Zero.