Naoto Miura is characterized by his obsession with clockwork machinery, to the point of being described as a machine fanatic and junkie. He devotes himself almost entirely to observing and tinkering with mechanical designs, often paying little attention to the people around him. His passion for machines set him apart from others at an early age, and by middle school he had already recognized that he was different from his peers. As a result, he was frequently bullied, though he responded with amusement, joking that he had earned a “Complete Set of Bullying” achievement.

Naoto values automata over humans, admiring the precision and permanence of mechanical creations in contrast to what he perceives as the flawed and transient nature of humanity. He openly dismisses human concerns, referring to people as “flesh-bags” and rejecting Marie Bell Breguet’s request to help repair Kyoto’s Core Tower on the grounds that he saw no reason to save its inhabitants. He only agreed when RyuZU mentioned that her younger sister lay beneath the tower. His loyalty to automata, particularly RyuZU, often outweighs concern for his own life, demonstrated when he instructed her to abandon him during the Kyoto purge and later injured his own hands pulling her overheated body to safety.

Naoto generally maintains a calm and unshaken exterior, rarely showing anger despite enduring humiliation from classmates and others. Beneath this composure, however, lies a darker side that surfaces whenever machines or automata are harmed. In such cases, he becomes consumed by bloodlust and vengeance, his eyes and smile taking on a warped expression. He views this not as vengeance but as a belief that individuals must always face the consequences of their actions, a principle he applies even to himself. Princess Houko remarked that this nature makes him both a powerful ally and a dangerous enemy, while Marie admitted she could not envision defeating him in a confrontation. Naoto also takes risks only when he feels a reward subjectively defined by his own values justifies the danger.

Despite these traits, Naoto is defined by an unyielding determination. He refuses to give up, even in dire circumstances, and combines his instinctive understanding of clockwork with unorthodox problem-solving. His unconventional thinking allows him to devise solutions others deem impossible, such as repairing RyuZU, confronting Gennai with an answer about humanity, and uncovering terrorist plans initially discovered by Vermouth.

Naoto also exhibits a perverse streak, alternating between masochism when abused by RyuZU and assertiveness in interactions with TemP. However, he maintains a sense of restraint and chivalry, refusing to act on his desires with RyuZU despite her provocations. He explains this as treasuring his automata too deeply to view them as objects of lust, though RyuZU herself is unimpressed by this reasoning.

Naoto Miura is depicted as a young man with pale grey eyes rendered blue in the manga adaptation and blue hair. His clothing style reflects his obsession with machinery, as he typically wears a blue hoodie layered over a matching shirt and paired with dark blue trousers, all featuring clockwork themed patterns. A distinctive aspect of his appearance is his constant use of neon-green noise cancelling headphones, which he wears almost at all times and which emphasize both his eccentricity and reliance on his heightened sense of hearing.

Superhuman Hearing
Naoto possesses an extraordinary sense of hearing, far beyond human limits. This ability allows him to detect even the faintest sounds, accurately determining both the location and number of sources within range. To manage this heightened sensitivity, he wears neon-green noise-cancelling headphones that reduce auditory input to normal human levels.

His ability is demonstrated most prominently during the Kyoto Core Tower incident, where he identified every malfunction in the tower’s massive gear system within seconds. This accomplishment contrasted with the Meister Guild, which had spent days attempting to locate the same faults without success.

Genius Intellect
Naoto is a clockmaker with an innate, almost instinctive understanding of clockwork mechanics. He was able to repair RyuZU within three hours, astonishing both her and Marie Bell Breguet, and surpassed the accumulated technical knowledge of the Breguet family, who had long possessed her.

Marie later admitted that Naoto’s hearing alone would have been enough to make him a genius mechanic. Initially, his inability to follow standard lessons and textbooks was attributed to personal shortcomings, but it was later revealed that the material itself was flawed. Naoto’s natural intuition conflicted with what he was taught, and once he abandoned conventional methods to rely solely on his hearing and instincts, his skills advanced to what has been described as near god-like levels of precision and speed.

Weaknesses
Naoto’s heightened sense of hearing also leaves him vulnerable. Without his headphones, the overwhelming influx of sounds can cause severe discomfort and debilitating headaches similar to migraines. In addition, his lack of physical training leaves him easily fatigued.

Despite his talents, Naoto remains human and physically unremarkable. As such, he is susceptible to conventional threats such as snipers or assassins. This vulnerability was exploited by Halter, who was able to take him hostage, forcing RyuZU and AnchoR into submission.

Unnamed Automaton
Before meeting RyuZU, Naoto devoted much of his time to an inactive automaton, treasuring her deeply despite being unable to restore her. Following her destruction, he was devastated but accepted that she could not be repaired. Instead, he salvaged her surviving parts and used them to complete the restoration of RyuZU. As a result, the affection he once held for the automaton carried over to the first unit of the Initial-Y series.

RyuZU
RyuZU becomes Naoto’s companion after he reactivates her and is registered as her master. She refers to herself as his “slave,” though their relationship grows into something deeper. Naoto frequently prioritizes RyuZU’s well-being over his own, and in turn, she remains fiercely protective of him, eliminating any threats to his safety and even punishing herself when he is harmed because of her. Their relationship develops romantically, culminating in Naoto proposing to her, which she accepts.

Marie Bell Breguet
Naoto initially harbors disdain for Marie, dismissing her as a “fleshbag” and often contradicting her simply to irritate her. Over time, particularly after the Kyoto events, he comes to respect her exceptional skill as a clockmaker, though he continues to treat her as a rival.

Marie respects Naoto in return, though she struggles with feelings of envy toward his extraordinary hearing and intuitive grasp of clockwork. Despite her own prodigious talents, she sometimes fears she cannot match him. Frustrated by both his brilliance and his dismissive attitude, she frequently calls him an “idiot.”

Vainney Halter
Halter often serves as a guiding figure for Naoto, knowing how to manipulate him into action when needed. Though blunt in his methods, Halter consistently prioritizes the safety of both Naoto and Marie, ensuring they are protected when situations escalate.

The given name Naoto (ナオト) is a common Japanese masculine name that can be written with various kanji combinations, often carrying meanings such as “honesty,” “straightforwardness,” or “truth.” In the series, it is written in katakana (ナオト), which does not assign a specific meaning but emphasizes phonetic expression.

His surname Miura (見浦) combines mi (見), meaning “to see” or “observe,” and ura (浦), meaning “bay” or “seashore.” Together, the name can be interpreted as “watching the bay” or “observer of the shore,” which reflects Naoto’s role as an observer of the intricate mechanisms of the Clockwork Planet.