Naoko Watanabe is a 16-year-old girl cursed with an involuntary transformation into Gauko, a fire-breathing dinosaur creature, whenever her anger reaches maximum levels. Everyday frustrations—annoying classmates, unfair situations, or encounters with troublemakers like the alien Bibilian—trigger these outbursts. Though Naoko actively tries suppressing her rage to prevent becoming Gauko, she often fails, resulting in destructive rampages. Physically, Naoko appears as an ordinary adolescent with curly brown hair, usually wearing a yellow top with a white collar and a pink skirt. Her dinosaur form, Gauko, manifests as a large, green-skinned creature capable of breathing fire and causing significant property damage. Elements of Naoko's clothing, specifically her cardigan and skirt, remain visible on Gauko. Naoko feels regret after the destruction but doesn't fear the transformation itself; she resents the social stigma and misunderstandings directed at Gauko. Naoko's personality blends typical teenage interests with the burden of her secret. She enjoys poetry, nature, strawberries, pudding, and her mother's cooking. She harbors a significant crush on Toshio Hiraga, finding him physically attractive and admiring his personality. Her best friends, Kana and Erika, accept her dual nature and support her despite the chaos. Classmate Takashi Yamada annoys her with persistent sports invitations, often provoking her anger. She maintains a close, sibling-like bond with Leonard while actively disliking the alien Bibilian and his companions for complicating her life. Her character evolves through various series challenges. Early episodes show her struggling to adapt to a new school and conceal her secret, including anxiety over school photos and social interactions. A significant development occurs when she becomes trapped in her Gauko form, unable to revert despite her friends' calming attempts. Further experiences include confronting an impostor Gauko and grappling with her identity under Keisuke Saito's guidance on anger management—advice which leads to unintended consequences among her peers. Family relationships are explored through storylines like investigating her frog-like father's suspicious behavior and participating in her mother's birthday celebration. The transformation metaphor reflects adolescent emotional turbulence, illustrating how intense feelings can overwhelm self-control while emphasizing that such emotions don't define one as monstrous. Her experiences highlight themes of acceptance within her diverse community, including non-human characters like her father, coexisting without judgment.