Born shortly after midnight as Tsuyuno Hinomoto, the younger twin daughter of Makoto Hinomoto, Tsuyuno faced tragedy immediately. Her biological mother died during childbirth and her father vanished, leading to both twins being placed for adoption. Adopted by the childless Yatsumura couple, Tsuyuno lived happily until a burglar, Soji Odano, broke into their home. Odano murdered her adoptive parents and their unborn child, sparing Tsuyuno only to threaten her with a return when she was older, leaving her in prolonged fear and isolation. This trauma forged Tsuyuno into a reserved, emotionally detached individual with a cold, blunt demeanor. She possessed analytical intelligence, frequently speaking at length about the mechanics of the Magical Girl Site and its inherent dangers. Her initial readiness to use lethal force stemmed from a desire for revenge; she captured Odano and subjected him to ongoing torture using her magical powers. Her powers originated from the Mahou Shoujo Site, granting her a smartphone-shaped "stick" enabling time-freezing abilities. Activating this power triggered physical changes: her blonde hair tips turned orange, a crescent moon emblem appeared in her eyes, and blood seeped from her mouth. Typing names into the phone allowed her to exempt individuals from the time freeze. Later, as an administrator ("Ni"), she gained the ability to freeze time through clapping and could discharge rose-colored plasma energy. She also temporarily wielded other magical sticks, including ones for mind control, force field projection, long-distance magic, and slicing, though each use exacted a toll on her lifespan. Her relationship with Aya Asagiri catalyzed her emotional development. Initially approaching Aya as an ally for survival, Tsuyuno gradually displayed warmth and protectiveness, forming a deep bond that softened her detached exterior. This connection culminated in a romantic undertone, including a kiss before her death. She repeatedly risked her life for Aya, such as overusing Mikado Ikemata's force field stick to shield her, an act which induced a coma and halved her remaining lifespan. A pivotal revelation confirmed Tsuyuno and Aya were biological twins separated at birth, though Tsuyuno remained unaware of this connection throughout most events. In an alternate timeline created by Aya's time manipulation, Tsuyuno's adoptive family survived Odano's attack, preventing her magical girl destiny. In this reality, she sensed Aya's presence but lived without the associated trauma. Physically, Tsuyuno had fair skin, short blonde hair, and golden eyes, typically seen in her school uniform—a black sailor shirt, skirt, and knee socks. Her personal traits included vegetarianism, an aversion to hospitals and meat, and interests in mobile gaming, swimming, honey, yogurt, and mascot characters. She expressed emotions subtly, often maintaining a blank expression even when amused. Her story concluded with death due to lifespan depletion from excessive magic use, though she was later implied to reincarnate as the administrator Ni. Her legacy persisted through Aya's efforts to reshape their past, ensuring Tsuyuno lived peacefully in the revised timeline.