Hanako, the famous old koi
Key facts: Hanako (花子) was a scarlet koi reportedly owned by Komei Koshihara and said to have died in 1977 at an age of 226 years, based on a 1974 study of growth rings on her scales[1][2].
Hanako is the name most often associated with claims of extreme longevity in nishikigoi (錦鯉), the ornamental koi of Japan[3]. She was reportedly kept in a pond in Higashi Shirakawa (東白川), Gifu Prefecture, and became widely known after a scale analysis suggested she was far older than any previously documented koi[2][1].Her reported age of 226 years was included in the Guinness Book of Records published in 1983, and the story has since been repeated across hobbyist and commercial koi literature as evidence that koi can live for centuries[2][4]. However, the aging method used has since been questioned by the All Japan Nishikigoi Promotion Association (JNPA) and by fact-checkers, making Hanako as much a case study in the difficulty of aging koi as a record of longevity[2][1].Reported history
According to Wikipedia, Hanako (花子) was purportedly born around 1751 and died on July 7, 1977, having been owned over her long life by several individuals, the last of whom was named Komei Koshihara[1]. The All Japan Nishikigoi Promotion Association states she lived in a pond in Higashi Shirakawa, Gifu, and describes her story as symbolizing the idea that “koi live long”[2].A koi dealer, Kodama Koi Farm, gives a somewhat different account, referring to her owner as the first president of the All Japan Koi Promotion Association, named Komei Etsuhara, who kept Hanako using water drawn from the Kiso River (木曽川) in Gifu Prefecture; this source states Hanako died in 1977 at a length of 30 inches (about 76 cm)[4]. This account's naming of the owner differs from Wikipedia's reference to Komei Koshihara, and readers should treat the owner's name as unresolved between sources[1][4].The scale-aging study and the 226-year figure
According to Wikipedia, Hanako's age was first examined in 1966, when two of her scales were removed and analyzed; at that time she weighed 7.5 kg (17 lb) and measured 70 cm (28 in) in length, and the initial analysis put her age at 215 years[1]. In July 1974, a further study of the growth rings on one of her scales concluded that she was 226 years old, the figure that has since been repeated as her age at death[1][3].The 1966 estimate is attributed by Wikipedia to a scientist named Masayoshi Hiro, reportedly of the Laboratory of Animal Science at Nagoya Women's University, though Wikipedia notes that the fact-checking site Snopes could not locate any peer-reviewed study by Hiro confirming the age[1].Guinness recognition and public attention
The claimed age of 223 years — a figure given by the JNPA as the basis of the Guinness listing — led to Hanako being included in the Guinness Book of Records published in 1983, after which her story became widely discussed as proof that koi could live exceptionally long lives[2]. Wikipedia similarly reports that she is widely cited as the longest-lived koi fish ever recorded, though it notes dispute over the veracity of this claim[1].Disputes over her true age
The JNPA states that the 223-year figure is now considered incorrect, explaining that it arose from a misunderstanding that scale ridges form at a rate of one per year, similar to tree rings[2]. In fact, according to the JNPA, many ridges can form within a single year, particularly while a koi is young and growing quickly, in the same way that humans grow fastest from birth to about age one and mostly stop growing by age 18; koi scales likewise stop producing new growth once the fish's growth slows, which the JNPA says makes scale-based aging unreliable for koi that have passed their main growth stage[2].Wikipedia reports similar skepticism, citing Snopes' inability to find conclusive evidence for Hanako's age, and quoting Dave Catania of the California Academy of Sciences, who stated that using scales is “the least accurate method of aging carp,” suggesting that extracting otoliths after death would have given a more accurate figure. National Geographic is reported to have noted that Hanako's age may “just be a legend”[1].Typical koi lifespans by comparison
The JNPA states that the actual lifespan of nishikigoi is generally around 30 to 40 years, depending on the environment in which they are kept, and notes that the period during which a koi retains its ornamental value is shorter still[2]. Wikipedia states that koi have been reported to achieve ages of 100–200 years, while also noting that some sources give an accepted age for the species of little more than 50 years[3]. A koi dealer, Kodama Koi Farm, states that nishikigoi can live over 200 years if kept in the right way, and links nutrition to overall longevity[4].Significance for the koi hobby
Hanako's story continues to be cited in both hobbyist and commercial koi literature as an illustration of the species' potential for long life, even as the specific age claim is treated with caution by organizations such as the JNPA[2][4]. The episode is also referenced in discussions of koi lifespan and aging more broadly, and of koi scales and skin, since the aging method in question relies on interpreting scale growth rings[2][1].Common questions
How old was Hanako the koi when she died?
Hanako was reported to be 226 years old at her death in 1977, based on a 1974 study of the growth rings on one of her scales, according to Wikipedia[1].
Is Hanako's 226-year age considered accurate today?
Where did Hanako live?
Was Hanako listed in the Guinness Book of Records?
Yes, the JNPA states she was included in the Guinness Book of Records published in 1983 based on her estimated age of 223 years[2].
Related koi topics
References
- ^ Hanako (fish) (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Hanako_(fish). Retrieved November 2026.
- ^ Ancient koi “Hanako” - All Japan Nishikigoi Promotion Association. All Japan Nishikigoi Promotion Association. jnpa.info/en/column/25/. Retrieved November 2026.
- ^ Koi (Wikipedia). Wikipedia. en.wikipedia.org/wiki/Koi. Retrieved November 2026.
- ^ Essential Nutrients & Supplements for Koi Growth & Color. Kodama Koi Farm (koi dealer). kodamakoifarm.com/essential-nutrients-supplements-for-koi-growth-co…. Retrieved November 2026.