Usagi Tsukino, known as Bunny Tsukino in some international adaptations, is the civilian identity of the title character from the anime Sailor Moon SuperS. She is a fourteen-year-old schoolgirl who lives in the Azabu-Juban district of Tokyo with her parents, Ikuko and Kenji Tsukino, and her younger brother, Shingo. Physically, she is recognizable by her distinctive hairstyle, which features long blonde hair styled into two high buns, often with pigtails, and her blue eyes. Her name is a play on words, as "Usagi" translates to "rabbit," linking her to the Asian folktale of the Rabbit on the Moon.

Her personality is characterized by a cheerful, carefree, and often lazy disposition. She is an underachiever in her schoolwork, particularly disliking mathematics and English, and would much rather eat sweets, play video games, read manga, or sleep than study. She is famously clumsy and accident-prone, with a tendency to cry easily when things do not go her way or when she is frightened, with common fears including dentists, ghosts, and lightning. Despite these flaws, her defining trait is her profound kindness, compassion, and an unwavering belief in the inherent goodness of others. She is deeply loyal to her friends and family, and her greatest dream is to one day become a bride.

In Sailor Moon SuperS, Usagi's role as the leader of the Sailor Guardians is well-established. Her primary motivation is to protect the Earth and the people she loves from any threat, using the power of the legendary Silver Crystal. While she can be a reluctant hero who would rather live a normal life, a sense of duty and her loving heart drive her to fight as the Guardian of Love and Justice. Her leadership is not based on intellect or physical strength, but on her capacity for empathy, hope, and love, which often prove to be the most powerful forces against evil.

Key relationships are central to her character. She is guided by Luna, a talking black cat who acts as her mentor. Her romantic partner is Mamoru Chiba, the reincarnation of her past life's lover, Prince Endymion, who fights alongside her as Tuxedo Mask. Their relationship deepens throughout the series, and her love for him is a significant source of strength. Another critical relationship is with Chibiusa, her future daughter from the 30th century. In the SuperS series, their dynamic often resembles a sibling rivalry, marked by bickering, but it is underlaid by a powerful mutual affection and protectiveness.

Throughout the story, Usagi undergoes notable development. She begins as a naive and reluctant heroine who often requires rescue, but she matures into a confident and capable young woman. Although she retains her cheerful and sometimes silly demeanor, she becomes more proactive and strategic in her role as a Guardian, relying less on guidance and showcasing a stronger will to protect others, even at great personal cost. Her core philosophy of seeking to heal and redeem her enemies rather than destroy them becomes a hallmark of her character.

As a fighter, Sailor Moon possesses a wide array of notable abilities, primarily derived from the immensely powerful Silver Crystal. Her powers are centered on themes of the moon, light, love, and mystery. Early attacks evolve into more potent techniques, such as Moon Princess Halation, which she executes using magical items like the Cosmic Heart Compact. In the Sailor Moon SuperS anime, she accesses a more advanced form known as Super Sailor Moon, which features a more ornate uniform with white accents and wing-like shoulder pads, granting her increased power. Her ultimate ability is not just destructive force, but powerful healing magic that can restore enemies to their original, uncorrupted states, reflecting her core nature as a protector and redeemer.