"I targeted First Studio where the largest number of people [at the company] work. I thought I would be able to injure many people," the suspect said, as quoted by the investigators and cited by the Kyodo News outlet.
Aoba expects to receive the death sentence.
On Friday, Kyoto's prefectural police questioned Aoba for the first time since the July 18 attack, which killed 36 people. He was being treated for burns and was unfit for questioning prior to Friday.
On July 18, a man, suspected to be Aoba, entered the the three-story Kyoto Animation studio, poured gasoline on the floor and ignited it. He was subsequently detained by police with major burns. During his detention, Aoba is believed to have said that the studio had stolen a novella from him.