Greycoat Research
began with a grey-coated cat
Our journey began in 2019, when the internet's favorite grey cat, TT, was diagnosed with kidney disease.
Claire, Greycoat Research's founder and TT's caregiver, began looking for better ways to support her daily care.
From that search, Greycoat Research was born for cats with kidney health concerns, and for the people determined to care for them well.
Our Story, in Videos
Every chapter, on Camera
One diagnosis changed everything.
In 2019, TT, the grey cat behind Greycoat Research, was diagnosed with chronic kidney disease. It started quietly, with a loss of appetite. Then, little by little, kidney disease began to affect her daily life.
By 2021, her checkups suggested that her heart was also under additional strain. According to IRIS staging guidelines, cats with Stage 2 chronic kidney disease are often described as having a median survival time of around three years, a number that made TT's future feel much closer than expected.
So Claire started searching, not for a miracle, but for better ways to support TT's care.
Spring 2021: TT visits the vet for a routine checkup.
Two years into CKD care, signs of heart strain begin to appear.
Three years in, "good enough" no longer feels enough.
"I definitely think Titi is cut out to be an only child. She looks happy when she's surrounded by other kids at home, but she seems super excited that her mom and the others are doting on her, even though the office environment is different."
— @먐먐*** · 2.9K likesThe routine became part of the care.
In 2022, TT's care entered a new phase. Claire started incorporating research from Dr. Toru Miyazaki and other researchers around the world into TT's kidney support routine.
With monthly bloodwork and careful daily tracking, TT's care became more structured. It took time, and there were difficult days, but both TT and Claire gradually found their rhythm.
CKD care is not built in a week or two. For cats and their caregivers, daily routine is part of the care itself.
Claire brings a research-informed care routine into TT's daily life.
Illness teaches us what we wish we had known earlier.
Even on hard days, TT's kidney care becomes part of everyday life.
"ㅠㅠ My kitties... Even in my eyes, they are still kittens... but Lululala, who came in as the youngest, is already about 6 years old... time feels like it is flying by so fast. Age is enough once I get older, so I just wish my kitties could stay baby kitties for the rest of their lives... Let's live as baby kitties for about 5,000 years... ㅠ"
— @섭섭*** · 935 likesOne article. One scientist. One trip to Japan.
While searching every day for new research on cat kidney care, Claire came across an online article about Dr. Toru Miyazaki and AIM science. It sounded almost too good to be true, so she decided to look beyond the headline.
Claire traveled to Japan to meet Dr. Miyazaki in person, learn more about his research, and tell him about the cats and caregivers in Korea who were hoping for better options in kidney health support.
Dr. Toru Miyazaki explains the AIM protein.
Dr. Motoo Kobayashi shares how AIM research in cat kidney disease began.
Cat parents share their hopes for future AIM-based kidney support.
"Let's keep fighting until the day Titi and all the cats in the world can live peaceful lives without pain! I feel reassured knowing that Captain K and so many cat owners are with us.😎"
— @Me*** · 2.7K likesOur first supplement began where our story began: with TT.
After signing an agreement with Dr. Toru Miyazaki, Claire launched Greycoat Research's first kidney support supplement for cats in spring 2024.
Inspired by TT, the grey cat who started it all, this formula marked the beginning of Greycoat Research's work in kidney health — bringing research-informed care into everyday cat life.
Claire traveled to Japan to share the launch with Dr. Miyazaki, introduce the formula, and discuss the next steps for Greycoat Research.
Dr. Toru Miyazaki and Claire discuss cat kidney disease and AIM-based supplements.
Claire shares why the caregiver's role matters in CKD care.
Dr. Toshiro Arai and Claire discuss feline CKD and at-home care.
"Wow... You were originally a developer, then you developed cat litter and even made cat liquor while raising cats, and now that my baby is sick, you're even making supplements for feline kidney disease... I really can't describe it any other way than as the immense love of a great mother."
— @쪼그*** · 558 likesAIM science came closer to everyday care.
After the launch of Greycoat Dr. Toru, Greycoat Research's first kidney support supplement for cats, Dr. Toru Miyazaki visited Korea.
He first came to Claire's home, where he met her eleven cats, the cats whose daily care had shaped the beginning of Greycoat Research. Later, at a seminar in Korea, he met veterinarians and cat parents caring for cats with kidney health concerns.
The room listened closely. Dr. Toru Miyazaki — the scientist who first identified the AIM protein and has spent years working to apply that discovery to cat kidney care — needed no introduction.
On February 14, 2024, Greycoat Research hosted Dr. Toru Miyazaki's seminar in Korea.
Dr. Toru Miyazaki meets Claire's eleven cats.
Claire shares why Greycoat Research created a kidney support supplement for cats.
"I'll cast my vote that Butler played a part in this too. I think Janggun knows how much love is given to the children... That must be why he is putting all his strength into living his life to the fullest."
— @sg*** · 295 likesSeven years later, TT's story still brings quiet hope.
In spring 2025, Claire shared seven years of life with TT after her kidney disease diagnosis — the difficult days when TT struggled to eat, the months of frequent bloodwork, and the moments when giving extra water meant calming down one very unimpressed cat.
The hard days do not disappear. But with time, they become part of the story.
Seven years into Stage 2 CKD care, TT continues to enjoy active days — a reminder that long-term care is not built on one big answer, but on many small routines, kept consistently over time.
In 2025, TT enters her seventh year of CKD care.
CKD care has its hard days, but the joyful ones are just as much a part of the journey.
Claire shares TT's bloodwork records from seven years of CKD care.
"she can speak japanese, contribute to making giant leaps in kidney disease treatment research, run a business and successful youtube channel, care for and rescue multiple cats, care for her cat so much that she outlived the estimated prognosis for her disease. she is a true beast and my role model omg"
— @zs*** · 259 likesGoing global with people who love cats.
The Greycoat Research team traveled to Türkiye, a country known for its deep love of cats, as we prepared to take our first step beyond Korea.
During the visit, Greycoat Research formed its first international partnership with Felikan Farma A.Ş., a veterinary-specialized distributor in Türkiye led by Dr. Tarkan.
For us, going global means more than entering new markets. It means working with people who love cats, understand the realities of animal care, and share our commitment to bringing thoughtful kidney health support to more cats and caregivers.
Greycoat Research visits cat-loving Istanbul, Türkiye.
Türkiye is a country filled with people who truly love cats.
With our first global partnership, we hope to meet more people who love cats and live for their well-being.
"I am 84 and now live in Arizona, USA. I hope one day Grey Coat will have a contract allowing its supplements to come here. All my cats died of kidney disease . One lived 18 years. It breaks my heart that not all of them lived so Claire, I’ve watched you for years on uTube and love all you do. Your joy and laughter is wonderful. May you and your colleagues continue your good work for a long time…the world needs your dedication. Thank you from one who loves cats and all you do for them. Sandy"
— @sa*** · 245 likes
One cat's story became many.
When we saw what consistent care did for TT, we couldn't keep it to ourselves. Greycoat Research exists so that other guardians have what we wished we'd had — supplements built around the science, and a team that answers when you write. Each cat we've supported has shaped what we offer next.
Read their stories