TV-Series
Description
Rena Ryugu, originally named Reina Ryugu, hails from Hinamizawa before relocating to Ibaraki due to her mother's career. Her family fractured when her mother's affair led to divorce. Reina rejected her mother and internalized blame, triggering severe mental instability. In Ibaraki, she assaulted three classmates with a baseball bat, permanently blinding one, and shattered school windows. Hospitalized, she suffered hallucinations of maggots in her blood and believed Oyashiro-sama cursed her for abandoning Hinamizawa. After a self-harm attempt, she returned to Hinamizawa with her father, changing her name to Rena to shed "icky" associations.

In Hinamizawa, Rena presented a cheerful, caring demeanor, often tending to friends like Keiichi Maebara. She cultivated an obsession with "kyute" (cute) objects, frequently entering "kyute mode" where she relentlessly collected items—often from the local junkyard where she maintained a secret base in an abandoned van. Verbal tics like "hau" when excited and repeated phrases ending with "kana? kana?" marked her speech. Beneath her friendly exterior lay intense trauma, her behaviors serving as coping mechanisms.

Rena exhibited extreme reactions to lies or challenges to her belief in Oyashiro-sama, manifesting in violent outbursts. She confronted Keiichi Maebara in Onikakushi-hen over perceived hypocrisy, pursuing him with a hatchet. In Tsumihoroboshi-hen, she killed scam artists Rina Mamiya and Teppei Hojo to protect her father, then planned to dispose of their bodies. Later, reading Takano Miyo's scrapbook, she took schoolchildren hostage, convinced her friends had betrayed her. Keiichi intervened, halting further tragedy.

Her relationships featured a close, competitive bond with Keiichi, tinged with romantic tension. She respected club leader Mion Sonozaki but clashed with her regarding Oyashiro-sama. Rena frequently targeted Rika Furude and Satoko Hojo during "kyute mode" due to their punishment outfits. She resented Rina Mamiya for dating her father, viewing her as a threat to their family.

Years after the June 1983 events, Rena attended Gogura University with Keiichi and Mion by 1988. She witnessed the Three Families declare Oyashiro-sama's curse ended. In this timeline, she bore a son named Kihiro. In Higurashi Sotsu, her role diminished, but she appeared during the resolution of Rika and Satoko's conflict, observing Satoko's redemption and the village's transcendence of the curse cycles.