Naoko Watanabe is an ordinary middle school student with an extraordinary secret: intense anger transforms her into the dinosaur creature Gauko. This metamorphosis triggers when her irritation or rage exceeds a certain threshold, sometimes occurring involuntarily even at low anger levels. The intensity of her anger directly fuels Gauko's size and strength, potentially escalating her to immense proportions. While Naoko retains her human consciousness as Gauko, their personalities diverge sharply. Naoko herself is generally calm and conflict-avoidant, prioritizing harmony in her family and friendships. Gauko, however, embodies heightened aggression, impulsivity, and a volatile temper, frequently acting on immediate emotional urges. Though anger dominates, Gauko can also display fear, sadness, or happiness. Naoko struggles to control Gauko's actions, especially during growth spurts where Gauko becomes more feral. Their relationship is complex, sometimes described as Naoko becoming an angrier self, and other times Gauko seems a separate entity or manifestation of suppressed emotions. Gauko possesses distinct abilities tied to transformation: superhuman strength for throwing people or demolishing structures, fiery breath generating intense heat, and exceptional durability making her nearly impervious to impacts, falls, or explosions. A key power is growth, increasing her size proportionate to anger, potentially reaching dimensions comparable to large buildings. Enhanced senses like smell and general physical augmentation also intensify with rising anger. Naoko navigates typical adolescent challenges—friendships, school, family—while managing her secret. Key relationships include her aware parents, classmates Keisuke Saito and Halley Tomoyo, and antagonist Takashi Yamada. Her experiences often involve suppressing difficult anger, leading to Gauko incidents that complicate her social life. Character development unfolds through incidents. Early episodes show Naoko's fear and lack of control over Gauko, causing unintended destruction and awkwardness. Specific scenarios like being "Stuck as Gauko" highlight reversion challenges, or encountering other transformed beings like the alien Bibilian. Later developments involve confronting threats such as an imposter Gauko or Mecha Gauko, requiring Naoko to strategically utilize her Gauko form. This indicates developing, though inconsistent, mastery over her abilities for problem-solving or protection. The core narrative follows Naoko's ongoing effort to balance her normal life with the unpredictable reality of her transformations.