Reina "Rena" Ryūgū, born July 28, 1969, originally resided in Hinamizawa before relocating to Ibaraki Prefecture during her childhood due to her mother’s fashion design career. Her family fractured following her parents’ divorce, spurred by her mother’s affair and subsequent pregnancy with another man’s child. This turmoil ignited severe psychological trauma in Rena, who blamed herself for failing to detect the infidelity. Her guilt culminated in a violent mental breakdown: she assaulted three male classmates with a baseball bat, shattered her school’s windows, and was hospitalized. Supplementary material indirectly hints that the attack may have followed an attempted sexual assault, a theory speculated by fans. Upon returning to Hinamizawa, she discarded the "i" from her birth name "Reina," rebranding herself as Rena to shed the "icky things" tied to her past. She became a fervent believer in Oyashiro-sama’s curse, interpreting her family’s collapse and visions of maggots infesting her blood as divine retribution. These delusions, compounded by her diagnosis of Hinamizawa Syndrome—a fictional disorder blending schizophrenia and delusional parasitosis—propelled her unpredictable actions. Rena harbors an intense fixation on gathering "cute" items, frequently scavenging a local junkyard where she stores her treasures in a hidden van. Entering "Cute Mode," she gains heightened agility and resolve to claim objects or individuals she adores, ranging from dolls to friends in playful attire or younger companions like Rika and Satoko. This whimsy starkly contrasts her volatile reactions to threats or deception, marked by the menacing cry of "Uso da!" ("That’s a lie!") and wielding cleavers or bats. Her devotion to her father drives extreme measures, such as eliminating con artists targeting him in *Tsumihoroboshi-hen*. In this arc, she briefly holds schoolchildren hostage, convinced her friends conspired against her, until Keiichi Maebara’s persuasion quells her rage. Across narratives, she oscillates between ally and adversary, leveraging sharp perceptiveness to uncover secrets and deploying calculated ruthlessness when threatened. Later timelines, like *Higurashi no Naku Koro ni Rei*, portray Rena at 37 as a university-educated mother to son Kihiro. Spin-offs such as *Higurashi: When They Cry – Gou* feature her attending the Three Families’ ritual disbanding the curse, underscoring her transition into adulthood. Crossovers and games cast her in diverse roles, including investigator and collaborative fighter. Physically, Rena sports short orange hair, lavender-blue eyes, and a petite stature. Her attire alternates between a sailor uniform with a yellow ribbon and a white dress adorned with a purple bow, paired with thigh-high socks and boots. A bloodstained cap recurs as a haunting motif in pivotal arcs. Visual storytelling employs shadowed eyes to signal her descent into hostility or instability. Her bond with Keiichi intertwines nurturing concern with unspoken romantic undertones, though she sidesteps acknowledging Mion’s affection for him. Despite her fragility, she exhibits empathy toward others afflicted by Hinamizawa Syndrome, recognizing their anguish through the lens of her own suffering.