Naota lives in the city of Mabase with his father, Kamon Nandaba, and grandfather, Shigekuni Nandaba. His older brother, Tasuku Nandaba, moved to the United States to play baseball, which deeply affects Naota, as he both idolizes and resents his brother. He struggles with feelings of inadequacy, believing that he must prove himself in his brother’s absence.

Naota spends much of his time with Mamimi Samejima, Tasuku’s former girlfriend, who clings to him as a replacement for his absent brother. Though she often teases and flirts with him, Naota is unsure of his own feelings toward her, leading to further internal conflict.

His life takes a drastic turn when Haruko Haruhara a chaotic, guitar-wielding woman crashes into him with her Vespa and subsequently smacks him in the forehead with a Rickenbacker 4001 bass guitar. This seemingly random encounter unlocks Naota’s latent N.O. (Neurotic Overflow) abilities, allowing him to pull objects, including giant robots, from his head. His quiet life is soon disrupted by a series of absurd, over-the-top battles, all tied to the mysterious Medical Mechanica Corporation.

Naota has short brown hair and brown eyes. He typically wears a blue hoodie over a yellow shirt, gray shorts, and sneakers. His facial expressions often reflect boredom or mild irritation, reinforcing his desire to appear mature and indifferent. His posture and mannerisms reflect his internal conflict wanting to be cool and composed while struggling with feelings of confusion and self-doubt.

Naota is initially portrayed as detached, moody, and somewhat jaded for his age. He dislikes childish behavior and tries to act older than he really is, often rejecting the fantastical events happening around him with an air of indifference. However, beneath his cold exterior, Naota is insecure, emotionally confused, and yearning for validation.

His relationship with Haruko forces him to confront his emotions and insecurities. He is both drawn to and frustrated by her reckless, unpredictable nature. As the series progresses, Naota begins to shed his immaturity, realizing that adulthood is not about rejecting emotions but embracing them.

• The Arrival of Haruko
  Naota’s life changes when Haruko Haruhara literally crashes into him with her Vespa and strikes him on the head with her bass guitar. This unlocks his N.O. abilities, causing giant robots to emerge from his skull. Haruko, who claims to be a space officer investigating Medical Mechanica, moves into his house under the pretense of being a live-in maid, further entangling him in her schemes.

• Awakening N.O. Powers
  After his first encounter with Haruko, Naota’s forehead becomes a portal for objects from other dimensions, mostly used by Haruko to summon robots for her own purposes. This causes various strange phenomena, including his body being taken over by robots from Medical Mechanica. Despite initially wanting nothing to do with the chaos, Naota is repeatedly forced into situations where he must fight.

• Climax and Growth
  As the series progresses, Naota gradually matures and begins to take control of his own life. He eventually confronts Haruko about her true intentions and chooses to embrace his own feelings rather than suppress them. In the final battle, he fully activates his N.O. abilities and temporarily wields Atomsk’s power the entity Haruko has been chasing. However, rather than becoming a pawn in her plans, Naota makes his own decision, demonstrating his growth. By the end of the series, Naota returns to his normal life in Mabase. Though the world around him remains unchanged, he has matured, realizing that adulthood is not about rejecting emotions but learning to navigate them.