Taiga Aisaka is a high school student from a wealthy background whose life fractures due to her parents' divorce. Initially living with her father and his new wife, constant conflict drives her out after recognizing his prioritization of his new family. Though her father finances her independent apartment, this arrangement deepens her sense of abandonment and neglect. His subsequent bankruptcy and disappearance force her into the care of her remarried mother, who has started another new family. Taiga struggles to fit in, haunted by the fear she is an incompatible burden.

Physically, Taiga possesses a notably short stature, light brown hair, fair skin, and large brown eyes that combine into a delicate, doll-like appearance often perceived as cute. This contrasts starkly with her aggressive demeanor, earning her the nickname "Palmtop Tiger" among peers. She reacts violently to perceived slights or embarrassments, frequently kicking or hitting others, especially when her height, underdeveloped physique, or social ineptitude are mentioned. She carries a wooden sword. Despite her fierce exterior, she is fundamentally clumsy, failing at basic domestic tasks like cooking and cleaning, and relies heavily on others for daily sustenance.

Her personality is a complex blend of insecurity, loyalty, and emotional guardedness rooted in abandonment trauma. She presents as sarcastic, cynical, and quick-tempered, using brutal honesty or aggression as defense mechanisms to push people away. This masks profound vulnerabilities, including low self-esteem and a fear of rejection. She exhibits intense loyalty and protective instincts towards trusted individuals like her best friend Minori Kushieda. However, underdeveloped social skills cause misunderstandings and isolation. Early on, she forms a pact with classmate Ryuji Takasu to help each other pursue their crushes (Yusaku Kitamura and Minori), though their constant proximity fuels relationship rumors.

In the OVA "The True Meaning of Bento," Taiga resolves Ryuji's escalating obsession with outdoing Yusaku's extravagant bento boxes. After Ryuji brings a rice cooker to school in his extreme efforts, Taiga intervenes by sharing homemade onigiri with him. This act helps Ryuji understand that bentos symbolize the preparer's care and affection, not culinary competition, showcasing Taiga's capacity for subtle emotional insight beneath her brash exterior. The scene culminates in a group picnic where Taiga overcomes her shyness to share a bento with Ryuji, demonstrating her growing willingness to express vulnerability around him.

Taiga's development centers on gradual emotional maturation and confronting dependencies. Initially, she uses her crush on Yusaku as a "security blanket" to avoid acknowledging evolving feelings for Ryuji, fearing the fallout for her friendship with Minori. Her turning point comes after Yusaku confesses love for student council president Sumire Kano, forcing Taiga to confront her true feelings for Ryuji. She eventually confesses her love, acknowledges their codependency, and recognizes it inhibits her growth. To achieve independence, she temporarily leaves to reconcile with her mother and stepfamily, aiming to build self-sufficiency. By the series' conclusion, she returns to Ryuji as a more emotionally honest and less volatile partner, having taken concrete steps toward adulthood and mutual reliance. Her journey reflects a shift from using aggression as a shield to embracing vulnerability and accountability in relationships.