0359 GMT January 28, 2020
Aoba, who has been in custody since Thursday, the day fire engulfed the studio in the city of Kyoto, has not been arrested, Reuters quoted as NHK saying.
The explosive fire killed 33 people and 10 more were in critical condition, authorities said. It marks the worst mass killing since a suspected arson attack in Tokyo that killed 44 people in 2001.
The suspect carried out the attack because he believed his novel had been plagiarized, media said on Friday.
The man wheeled a trolley carrying at least one bucket of petrol to the entrance of the Kyoto Animation building in Kyoto city before dousing the area, shouting “die” and setting it ablaze on Thursday, broadcaster Nippon TV said, citing police.
“I did it,” the 41-year-old told police when he was detained, Kyodo news said, adding that he had started the fire because he believed the studio had stolen his novel.
Police declined to comment. Broadcaster Nippon TV said the suspect was under anesthesia because of burns he suffered and police were unable to question him.
Aoba, a resident of the Tokyo suburb of Saitama, some 480 km (300 miles) east of the ancient capital of Kyoto, was believed to have bought two 20-litre gasoline cans at a hardware store and prepared the petrol in a park near the studio, Nippon TV said.
He travelled to the area by train, the broadcaster said.
NHK showed footage of him lying on his back as he spoke to a police officer at the time of his detention, shoeless and with apparent burns on his right leg below the knee.
He had no connection with Kyoto Animation and his driver’s license gave an address in the north Tokyo suburb of Saitama.
None of the victims’ identities had been disclosed as of Friday. There were 74 people inside the building when the fire started.
The building did not have any sprinklers or indoor fire hydrants, though it was not legally required by the fire code, a Kyoto Fire Department official said.
Nineteen of the 33 who died were found on a staircase leading up to the roof from the third floor, bodies piled on top of each other, Kyodo said, citing authorities.
Firefighters arriving soon after the fire began found the door to the roof was shut but could be opened from the outside.
The victims may have rushed up the stairs to escape the blaze and found themselves unable to open the door.
The fire wasn’t put out until early on Friday.
Kyoto Animation, in a quiet suburb about 20 minutes by train from the center of Kyoto, produces popular “anime” series such as the “Sound! Euphonium”.
Its “Free! Road to the World - The Dream” movie is due for release this month.