Matsuri Mizusawa is a supporting character in the series Citrus. She is introduced as a second-year middle school student who later enrolls at Aihara Academy, the same school attended by Yuzu Aihara and Mei Aihara. She is the older sister of Inori Mizusawa, and her parents are frequently absent, leaving her largely unsupervised. Matsuri has known Yuzu since childhood; Yuzu approached her because she seemed lonely, and the two formed a close, sister-like bond. Matsuri grew possessive of Yuzu, often invading her space and demanding her attention.

Matsuri is precocious and intelligent, with a sharp wit and a mischievous, teasing nature. She frequently plays pranks on others, especially Yuzu and Harumi Taniguchi. Beneath her playful exterior, she is highly manipulative and cunning, using emotional intelligence and deception to get what she wants. She holds a cynical view of men, believing they are easily manipulated, and once earned money by selling internet videos to older men under false pretenses. Her early actions in the story are driven by a deep fear of abandonment. Having depended on Yuzu as a surrogate older sister, she becomes jealous when Yuzu develops romantic feelings for Mei. In an attempt to reclaim Yuzu’s affection, Matsuri kisses Yuzu in front of Mei, orchestrates a compromising situation to take a photo of Mei, and tries to use blackmail to drive them apart.

Despite her antagonistic debut, Matsuri’s motivations are rooted in emotional insecurity rather than genuine malice. As the story progresses, she acknowledges her faults and begins to change. Mei recognizes a similarity between them—both struggle to express emotions in healthy ways—and this shared understanding leads to a gradual reconciliation. Mei tutors Matsuri, and Matsuri helps Mei at school events and on a summer trip. Matsuri eventually comes to respect Mei, viewing her as an older sister figure, and actively supports her relationship with Yuzu. She offers Mei advice and remains a playful but kind presence in their lives.

Matsuri’s relationship with Harumi Taniguchi develops from initial wariness to a comfortable friendship. Harumi is the first to see through Matsuri’s schemes, and Matsuri enjoys teasing her. Over time, they spend more time together, and their interactions hint at a possible mutual crush, though this remains ambiguous. Matsuri also forms bonds with other characters in the main group, becoming an integrated member of the cast.

Notable abilities include her sharp intelligence, strong academic performance, and skill in psychological manipulation. She is an adept strategist who reads people quickly and uses social situations to her advantage. She has no supernatural or combat abilities, relying instead on her wits and charm. Visually, she is short in stature with shoulder-length light pink hair and bright blue eyes, often seen wearing a pair of headphones. Her fashion sense is casual and slightly edgy, reflecting her rebellious personality.

Matsuri undergoes significant character development, transitioning from a possessive antagonist to a supportive and emotionally open young woman. She learns to let go of her fear of being left behind and to express her care in healthier ways. Her growth is a key element of the series, illustrating themes of forgiveness, emotional maturity, and the complexity of familial bonds.