OVA
Description
Born Reina Ryuuguu, Rena moved from Hinamizawa to Ibaraki as a child due to her mother's fashion career. Her mother's affair and subsequent request for Rena to join her new family caused significant trauma. Rena's refusal contributed to her parents' divorce. Blaming herself, she developed mental instability, attacking three male classmates with a baseball bat and smashing school windows. Hospitalized afterward, she attempted self-harm, experiencing delusions about "filthy blood" filled with maggots—symptoms of undiagnosed Hinamizawa Syndrome. During this period, she adopted the name "Rena," dropping the "i" from "Reina" to symbolically remove "icky things." She returned to Hinamizawa believing Oyashiro-sama's curse necessitated it for safety.

Loyal to her father, Rena exhibits a dichotomous personality. Typically cheerful and naive, she obsesses over "cute" objects (かぁいい, "kaaii"), frequently scavenging at the village trash heap. She enters "Take Home Mode," attempting to claim desired items with heightened physical agility. This contrasts with intense hostility triggered by lies or challenges to Oyashiro-sama's curse, epitomized by her line, "Uso da!" (嘘だ!, "That's a lie!"). Her eyes lose visible light during these shifts, signaling menace. Perceptive and analytical, she deduces truths from minor details, like inferring characters' whereabouts from household objects. Mion Sonozaki warns others about Rena's capacity for frightening aggression beneath her cute demeanor.

Physically, Rena has short orange-brown hair in an angled cut and lavender-blue eyes. She wears a standard sailor school uniform with a yellow ribbon or a white dress with a purple bow and thigh-high boots. Her white beret, sometimes blood-stained, serves as a plot symbol in later arcs.

Rena's actions vary by story arc. In *Tsumihoroboshi-hen*, she kills scam artists Rina Mamiya and Teppei Hōjō to protect her father. After receiving Takano Miyo's scrapbook, she questions Oyashiro-sama's nature and her friends' trust, leading her to take schoolchildren hostage; Keiichi Maebara's intervention prevents further tragedy. *Minagoroshi-hen* showcases her strategic intimidation of village elders and child welfare officials, including a physical altercation. *Tsukiotoshi-hen* depicts her as an antagonist. *Nekogoroshi-hen* presents her in a lighter context, participating in a costume parade and investigating an abandoned village's quarry, though her role lacks significant development.

In sequels and spin-offs, Rena appears as a 37-year-old university attendee in *Higurashi no Naku Koro ni Gou*, aware of the curse's dissolution. *Higurashi no Naku Koro ni Rei* introduces Kihiro, her son, in its 2019 setting. Expanded media like *Higurashi no Naku Koro ni Kizuna* involve her in murder cases linked to her Ibaraki past.