Spoiler Alert! Click to show or hide
In reality, she is one of the main components of the eternally repeating June 1983, and is the only one who is consistently able to remember the past repetitions. She believes she has lived over 100 years by the time of Tsumihoroboshi-hen, but continues to act like a child in order not to alarm her friends. Prior to Matsuribayashi-hen, she is the only one able to see Hanyuu, who has been an "imaginary friend" to her all her life.
Rika seems like little more than a secondary character for much of the first season of Higurashi. As the story progresses though, viewers learn that she is actually at the very heart of most of the strange happenings in the series. The villagers of Hinamizawa hold her in high esteem. Not only is she the only daughter of Furude clan, one of the three great houses of Hinamizawa; she is also believed to be the reincarnation of the local deity Oyashiro-sama.
Rika often seems wise beyond her years, and as a very young child she predicted her own death in June of 1983 to the visiting Mamoru Akasaka. She has a tendency to speak using 'cute' phrases; including sound effects and nonsense words such as "nipaa", "mii", cat sounds and saying "pachi pachi" (clap clap) while clapping her hands, all of which drives the cute-loving Rena wild. Despite her 'cute' and feminine manner, Rika refers to herself with the word "boku", generally used by boys. She lives with her classmate and friend Satoko in a small house, and is fond of sake and kimchi.
Rika's cuteness disappears and she turns cynical and much more mature. She switches from "boku" to "watashi" and her voice drops to something more resembling a grown woman's voice than a child's. This is the voice and outlook on life Rika uses when thinking and when speaking to Hanyū, so it is likely this is her real personality, which she keeps under wraps to avoid scaring her friends. Rika's second character song is sung almost entirely with her true Personality, and it is notable Frederica Bernkastel sounds and acts almost exactly like this. The first time we know of her True Personality is in Himatsubushi-hen, when she warns Akasaka to go back with his wife to save her from dying. After that she fainted.
It appears that over the hundreds of repetitions she has been through, Rika's true personality has become understandably somewhat distorted and sly, as she seems to an extent to derive pleasure from taunting people with knowledge that she shouldn't know, such as Akasaka. Apparently Rika used to resist her fate with much greater enthusiasm, but she was worn down mentally over time, and eventually seems resigned to her fate. Due to this, she also seems to have practically no interest in anything, as she has been through it all many times already (save for Mion's whimsical club activities, which seem to be one of her few pleasures in life), and she welcomes any kind of change, good and bad. TIPS reveal that when her family was still around, she would show no emotions, and only react to something unexpected. This caused great concern for her mother, who couldn't understand Rika no matter how hard she tried, and made their relationship difficult. Her True personality is also considerably bold and sometimes rude to people.
Rika has long blue hair in a hime cut, fitting her image as a miko. Her eyes are fairly droopy and purple, and she is the shortest character of all.
On school days, Rika wears a white shirt with a pink bow, a navy-blue skirt, navy suspenders and brown shoes. On free days, she wears a green sundress and white sandals. During the Watanagashi Festival, she wears a traditional miko uniform, complete with a ornate hoe topped with tassels.
As a daughter of the Furude clan Rika is a "Queen Carrier". Early theories on the Hinamizawa syndrome hold that the Queen Carrier is necessary part of the village's survival, and that without her the villagers would go mad in 48 hours. This theory is later proven to be untrue, but some of the deference shown to Rika by the villagers may be an unconscious acknowledgement of her role as Queen Carrier. How exactly the status of Queen Carrier is handed down is unclear; although the research done on the Syndrome shows that it is passed down in the females of the Furude clan there is evidence of who the carrier was prior to Rika. It is because of this inheritance, however, that Takano Miyo pursues her as a research subject. Her parents refuse to allow Rika to be used in this manner and in order to get her way Takano is more than willing to get rid of them. In order to prove grandfather's theories satisfy her funders, Takano decides that, after years of observing, she needs to kill the Queen Carrier as well. Rika's death is the pivot point for each of the scenarios of Higurashi; on her death Takano will be able to wipe out the entire village with the forces at her disposal in order to 'prevent' the 'doomsday scenario' her grandfather predicted for the village.
Hanyū's powers allow her to 'reset' time after Rika's initial murder, and all subsequent deaths as well, leaving only the two of them with any clear memory of the events. Together they set out to solve the mystery behind Rika's death and prevent the disaster that follows, but each time Hanyū uses her ability the time they have grows shorter. After what Rika estimates to have been over 100 years of repeating the various scenarios over and over she begins to doubt that they'll ever solve it, despairing and nearly giving up until she realizes that some of her friends seem to remember bits and pieces of the various scenarios they've run into before. With the help of her friends she is able to deceive Takano and the groups backing her into believing that Rika has already died, and that the hypothetical 48 hours have passed with no apparent ill effect, saving both her own life and the village.
Out of all the characters, Rika has died the most number of times.
She is the only one (of all her friends) in the arcs (also counting the spin-off ones), to have never been a sole survivor.