Ruri (ルリ) is Kohaku's older sister and the daughter of Kokuyo, she is also a priestess in Ishigami village.


Ruri is similar to Kohaku in appearance but has longer hair and a more hourglass-shaped body. She wears a black sundress and a piece of rope around her neck.


Ruri was first introduced as a frail, ill woman. When she learned of Senku's presence in the village, she showed signs of natural curiosity and a keen memory, his name managing to stir up memories of one of Ishigami Village's stories. While appearing feminine, in reality she is as match a tomboy as Kohaku, immediately running around the village after making a full recovery from her illness with Senku's help. She is kind, caring and loving towards her friends and family. She has a rather submissive quiet nature stating she was fine with marrying whoever won the village tournament (though this could possibly be because she resigned herself to her fate and short life attributed to her disease). However, once she is cured of her disease, she is shown to be more optimistic and positive though still quiet and demure. She has a kind gentle demeanor and appears more feminine than her sister in some aspects (though can be quite a tomboy as well). She is childhood friends with Chrome who has strong feelings for her.


Ruri might share some of Kohaku's athletic prowess, as her first instinct when cured is to sprint off into a field at high speeds.

She is very observant, as she was able to tell Kohaku was in a dangerous situation, simply because her hair knot was different, most wouldn't have noticed this.


Ruri was born to the village chief in Ishigami Village at some point in time. She eventually became extremely sick around her 18th birthday. Kohaku manages to sustain her life using hot water that she gathers every day to slow down the disease progression.


Kingdom of Science Arc

She notices Kohaku's hair knot was different and questions what danger she faced that made her change her knot.

Village Games Arc

After Senku diagnose that she suffers pneumonia, she's willing to take a risk of consuming antibiotic for the first time. Eventually, she was healed right on time after proper treatment by Senku. She was divorced by Senku.

Village Origins Arc

She reveals that Ishigami Village was founded by Byakuya Ishigami and his crew.


  • Her name Ruri is the Japanese word for Lapis Lazuli. It is a type of Metamorphic rock.
  • She appears to be rather popular as Chrome, Magma, Ginro and Kinro have all shown an attraction towards her though she married Senku (for barely a day before he divorced her as he lacks interest in romance). It seems Chrome's feelings are the most sincere and genuine and it is implied in later chapters that she in fact reciprocates his feelings.
  • Her illness was initially unknown. Senku deduced based on how her lungs sounded that she had water in her lungs. After dissecting a rat, he further diagnosed that the inflamation in her lungs was caused by bacteria passed from rats. After Senku made an antibiotic (sulfanilamide) to cure her illness and she had an averse reaction where the bacteria started to act up as the number of infectious bacteria increased, he deduced she was infected with Streptococcus pneumoniae, which has the ability to hijack surrounding harmless bacteria with their own toxic genes to multiply the number of infectious bacteria in the body. In other words, the name of her disease was Pneumonia (as stated in chapter 41).


  1. Dr. Stone Manga; Volume 4, Q&A Section
  2. Chapter 99


v  e
Kingdom of Science
Male Taiju OkiSenku IshigamiGen AsagiriChromeKasekiKinroGinroMagmaRyusui Nanami
Female Yuzuriha OgawaRuriKohakuSuikaNikkiMinami
v  e
Post Petrification Humans
Male ChromeGinroJasperKasekiKokuyoKinroMagmaSoyuzTetsuken
Female GarnetKohakuRubyRuriSapphireSuikaShiroganeTurquoise
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