Dozens were killed and injured in a blaze which is suspected to be an arson attack.
Messages like, "Stay strong KyoAni. All of the anime community stands at your back. We will always catch you when you fall," are highlighting the special role the studio played for its fans.
More victims are thought to be unaccounted for, while some 40 people are in hospital, reports say.
Local police say they believe the fire was started by a man who broke into the studio on Thursday and ignited petrol.
A special studio culture
KyoAni was founded in 1981 and has produced popular animation shows including K-On and The Melancholy of Haruhi Suzumiya.
The studio also released a standalone feature anime A Silent Voice, in 2016.
One of KyoAni's series, Violet Evergarden, was picked up by Netflix for a global market.
"One of the main things that stands out about Kyoto Animation is the quality of the animation itself," said Ian Wolf, an anime critic for Anime UK News. "It's very viewer-friendly."
The distinctive visual style and level of polish leads to a look that is instantly recognisable, Wolf said.
"The studio makes very little in the way that is controversial... little that is violent or sexual. I can't imagine why anyone would want to attack it."
Some recent projects include Free, a show about a school boys' swimming team which has proved popular among women, and is set to have its own spin-off film to coincide with the 2020 Tokyo Olympics.
A Silent Voice, on the other hand, is a stand-alone film based on a manga by Yoshitoki Oima. It is about a bully who torments a classmate with a hearing impairment, but later must come to terms with his actions when he is bullied himself. The Guardian gave it a four-star review, calling it "a beguiling film: subtle, sensuous and delicate".
Aside from the quality of its content, the studio is also well regarded for the way it makes it. One Reddit user discussing the attack labelled it "a beacon of what the anime industry should be" for its staff policies and in-house training.
That, Wolf said, was partly down to how their staff were paid.
The studio is also known for paying its animators a regular salary, breaking with the industry's standard of paying per frame - which is seen as putting extreme pressure on staff.
Tributes and donations
"It's one of the best and largest animation firms in Japan," Tokyo-based film commentator Yuichi Maeda told Reuters news agency. "With that loss of life, many of the best hands at animation in the nation are likely to be dead."
He said the studio's impact on the industry was much larger than the number of works it made would suggest. "It's too painful to contemplate."
"It has a huge presence in animation here. To have this many people die at once will be a huge blow to the Japanese animation industry," he said.
While KyoAni may be best known in Japan, news of the attack led to a huge outpouring of support from the anime community across the world.
A GoFundMe campaign, started when the news broke, raised almost $100,000 (£80,000) in two hours, rising to more than $200,000 by 19:00 Tokyo time (10:00 GMT).
It was started by Sentai Filmworks, a US-based distributor of Japanese cultural works. The vast majority of donations were small amounts of $50 or less from fans.
"This company produced so many anime that helped shape me into who I am. Most of which were absolute masterpieces," wrote donor Darrian Harrison.
"KyoAni's works have been a part of my childhood," said LC Mendoza.
Another donor, Mackenzie Haa, said Kyoto Animation "is a model for the anime industry and deserves so much better than this. I hope they come back stronger than ever after this tragedy".
Across the internet, fans are posting messages of condolence and support on discussion forums and message boards.
Many are sharing their favourite shows, and observing how they were shaped by them over the years.
Most of the tributes and concerns were targeted squarely at the staff who may have lost their lives and their families.
But fans also lamented the potential artistic loss.
"Thousands of drawings, computers with important animation files. Whatever they currently have in the pipeline may be near or completely destroyed," one Reddit user wrote, though others argued backups must exist.
Others posted links to well-known staff who had tweeted they were safe - or kept lists of those still missing.
Credit to : www.bbc.com