Kinta Sakata is a high school student and a classmate of Ken Okarun Takakura and Momo Ayase. He is a self-proclaimed fan of classic science fiction and mecha anime, with a deep and obsessive passion for giant robots that has shaped his entire worldview and personal aspirations. His ultimate dream in life is to one day become the pilot of a giant robot.

In terms of personality, Kinta initially comes across as vain, arrogant, and deeply pretentious. He is a classic attention-seeker who often strikes dramatic poses and makes outlandish claims to appear important or impressive, such as wearing an eyepatch and bandages to school while fabricating a story about a solo battle against an alien. This behavior extends to his interactions with girls, whom he desperately wants to charm, but his attempts are clumsy and often misinformed. After misinterpreting a conversation about Okarun's missing testicles, he erroneously concludes that making crude jokes is the secret to popularity, which only serves to alienate others and earn him the derisive nickname Erosuke from Momo. Despite this, his irritating traits are balanced by a just heart and an ability to take decisive action when it truly matters.

Beneath his boastful exterior lies a significant amount of insecurity. Kinta is acutely aware that he is an outcast with mediocre academic and athletic abilities, and he feels invisible to his peers. His arrogant persona is a mask he uses to find comfort by looking down on those he deems beneath him and to hide his profound sense of inadequacy. This inner conflict becomes a core part of his motivation. He is driven by a powerful desire for recognition and to prove that he is not useless, a feeling that causes him great distress when he suspects the main group has left him behind. His journey from being a boastful loner to a dependable ally is a gradual one, but he ultimately proves his worth by embracing who he truly is: a person who loves robots and refuses to run from a fight, no matter how scared he is.

Kinta is introduced to the main story by his own design, having observed Okarun from afar and become envious of his newfound popularity with girls like Momo and Aira. He attempts to learn Okarun's secret, only to get pulled into a chaotic battle with a kaiju. His initial role is that of a disruptive and often unhelpful newcomer, but this quickly changes when he discovers his unique aptitude for a piece of alien technology known as nanoskin. Unlike the other characters who rely on spiritual or parasitic powers, Kinta's abilities are entirely derived from his mastery of this shape-shifting material. His vivid imagination, fueled by years of consuming mecha anime and practicing on amusement park rides to avoid motion sickness, makes him exceptionally skilled at visualizing and constructing complex structures with the nanoskin. He can form it into anything from a motorcycle to a surveillance camera hairpin, but his most notable creation is the Great Kinta, a colossal, Buddha-like giant robot assembled from the remnants of the Ayase house.

His key relationships are primarily with the other members of the main group. He harbors a competitive jealousy toward Okarun and Jiji, the latter of whom he nicknames for his good looks and open personality. He sees Momo as a bossy but admirable senior figure and is endlessly hopeful for positive attention from Aira. Despite his irritating quirks, his actions eventually earn him a place in the group, and he becomes a crucial asset in their most dangerous battles, forming a unique bond with Bamora after rescuing her. Kinta Sakata's development transforms him from a comic relief character defined by his flaws into a surprisingly competent and courageous figure whose creativity and refusal to give up prove that heroism can come from the most unexpected of places.