•Shinji Aoba, 45, pleaded guilty to the attack but his lawyers had sought a lighter sentence, arguing grounds of "mental incompetence".
•Many of the animation staff were killed after being trapped on the upper floors of the studio as the fire spread.
A Japanese man has been sentenced to death for an arson attack at a Kyoto animation studio in 2019 which killed 36 people and injured dozens more.
The incident, one of Japan's deadliest in recent decades, killed mostly young artists and shocked the anime world.
Shinji Aoba, 45, pleaded guilty to the attack but his lawyers had sought a lighter sentence, arguing grounds of "mental incompetence".
Judges rejected this however, ruling Aoba knew what he was doing.
"I have determined that the defendant was not mentally insane or weak at the time of the crime," Chief Judge Masuda said on Thursday at Kyoto District Court.
"The death of 36 people is extremely serious and tragic. The fear and pain of the deceased victims, indescribable," he said according to NHK reports.
Many of the animation staff were killed after being trapped on the upper floors of the studio as the fire spread.
One of the most shocking cases in recent decades in Japan, the incident sparked national mourning. The country's public and media have followed the case closely.
Prosecutors had demanded the death penalty saying Aoba, an author, was motivated to attack the studio after believing his work had been stolen. He said Kyoto Animation had plagiarised a novel he entered into a contest run by the firm.
In July 2019, he burst into the studio during a work day, splashing petrol on the ground floor and setting it alight while repeatedly shouting "Drop dead".
He later said during his guilty plea in September 2023 that he didn't know how many people would become trapped in the building.
"I felt I had no other option but to do what I did," he said at the time.
"I feel tremendously sorry and the feeling includes a sense of guilt."
Aoba himself suffered burns to over 90% of his body in the fire, and was only arrested after he recovered from operations.
"The delusion that Kyoto Animation Studio had plagiarised his work influenced his motivation," prosecutors had told the court.
But they said he was not controlled by the supposed delusions and had full capacity and knowledge of his actions.
The judge read out a lengthy reasoning with victim testimonies before announcing the verdict on Thursday. More than half of the animation studio's 70-strong workforce was killed in the event, and another 32 injured.
"Some of them saw their colleagues engulfed in flames, and some of them are suffering from psychological effects, and they are tormented by feelings of guilt and remorse," said Judge Masuda.
Families of the victims were seen in the court room, with some wiping tears as the judge read out the details of the Aoba's crime, Japanese broadcaster NHK reported.
The outlet reported that Aoba kept his head bowed as the judge read out the death penalty sentence.
Japan retains the death penalty for its most serious crimes, like multiple murders.
The KyoAni studio in Kyoto is a beloved institution, known for producing films and graphic novels that were critically well-regarded by fans - including K-On! and The Melancholy of Haruhi Suzumiya.