Sakura Yoshino is a third-grade student secretly wielding special powers in her T.P. Sakura persona. As a time-traveling magical girl working for her grandmother's temporal defense agency, she protects historical timelines from disruptions. Her missions frequently pit her against the time-traveling thief Suginami, whose well-meaning motives—like rescuing a puppy or tweaking minor history—lead to comedic situations and moral clashes over timeline rules.

Across the broader Da Capo series, she is Jun'ichi Asakura's older cousin and first love. Despite her actual age, a self-made wish to remain as Jun'ichi remembered her grants her perpetual youth, locking her appearance as a young girl. This agelessness endures decades later, evident when she appears unchanged as director of Kazami Academy in Da Capo II. Possessing an IQ of 180 and potent magic inherited from her grandmother, her power unconsciously twists her strong emotions and wishes into reality, sometimes causing dangerous unintended consequences when fueled by jealousy or distress.

Her personality blends intellectual brilliance with deep emotional layers. She displays lively mischief and profound affection for Jun'ichi, often using the pronoun "boku." Yet flashes of temper, jealousy (especially toward Nemu Asakura), and insecurity about her childish look and flat chest surface. Three unfulfilled childhood promises with Jun'ichi—including one pledging future romance—linger due to his relationship with Nemu, feeding her emotional volatility. In later years, she merges a witch's wisdom with childlike quirks and cultivates a new magical cherry tree species on Hatsune Island, suggesting further undisclosed wishes.