OSAKA (Kyodo) -- A man charged with the 2019 fatal arson attack on a Kyoto Animation Co. studio has dropped his appeal to overturn his death sentence, a Japanese high court said Tuesday, finalizing the verdict over one of the country's worst mass-murders.

Shinji Aoba, 46, was sentenced to death by the Kyoto District Court in January 2024 for the attack that killed 36 people at the internationally famous animation production studio, after the court found him mentally competent to be held accountable for his crimes.

The defense team for Aoba, and subsequently the defendant himself, appealed the death sentence. But Aoba withdrew his appeal on Monday, according to the Osaka High Court, where the trial was set to take place.

In Japan, there have been cases in the past in which the validity of a defendant's withdrawal of an appeal is contested by the defense lawyers. Aoba's defense team has not made a statement regarding the latest development.

A lawyer for Kyoto Animation, Daisuke Okeda, declined to comment, saying that the company cannot respond unless the "situation has been settled."

According to the ruling by the Kyoto District Court, Aoba entered the Kyoto Animation studio's premises at around 10:30 a.m. on July 18, 2019, where 70 employees were working. He set the building on fire with gasoline, killing 36 people and injuring another 32.

As Aoba had confessed to his role in the incident, the focus of the trial had been whether he could be declared mentally competent and thus held criminally responsible.

The defendant said he carried out the attack under the belief that Kyoto Animation plagiarized a novel he entered in a contest run by the firm. His defense team had sought an acquittal or lesser sentence, arguing Aoba was not of sound mind and was suffering from delusions.

The Kyoto District Court acknowledged in its ruling that Aoba did suffer from a delusional disorder, but that his conduct was little affected by it.

He was expected to contest his criminal liability at his appeal trial.

Kyoto Animation, often referred to as "KyoAni," is known worldwide for producing hit anime works including "K-On!" and "The Melancholy of Haruhi Suzumiya."

Relatives of the victims remain angry at the defendant, with some questioning the reasoning behind him withdrawing his appeal.

"I was uncertain about the future and worried about how long this was going to last. It still doesn't feel satisfying, but there's some sense of relief," said the 74-year-old grandfather of Megumu Ono, who was killed in the fire when she was 21.

While Aoba said he "felt sorry" toward the end of the trial, the grandfather has thought it was far from an apology.

Ono's grandmother has struggled with resentment, questioning why Aoba is still alive when she prays for Megumu every morning and night.

Another bereaved family member wondered what change of heart happened in Aoba, saying, "Is it his way of showing an apology?"