OMIYA • The suspect who killed 34 people in an arson attack in Japan lived alone, playing video games non-stop, and had "terrified" his neighbour just days before he travelled hundreds of kilometres to the Kyoto Animation studio which he torched.
Police late on Saturday issued an arrest warrant for 41-year-old Shinji Aoba, suspected of causing Japan's worst mass killing in two decades two days earlier.
He had gone to the studio in Kyoto, poured fuel around the entrance and shouted "Die" as he set the building ablaze, according to public broadcaster NHK.
They plan to arrest Aoba, who suffered serious burns and was airlifted last Saturday to a university hospital for treatment, once he recovers, NHK said.
Police said Aoba had previously been convicted of robbing a shop.
Aoba lived alone on the ground floor of a two-floor apartment building on the outskirts of Omiya, a commuter suburb of Tokyo and some 500km east of Kyoto.
His next-door neighbour recalled Aoba as pudgy and unkempt, with blemished skin. He kept odd hours and barely spoke to anyone.
"I've never seen him go out during the day, not even to the convenience store. I would regularly hear him go out around midnight," said the neighbour, a 27-year-old man who declined to be identified.
Music from video games blared from Aoba's unit at all hours, the neighbour said, adding that there had been complaints from residents about the noise last year.
On July 14, days before the attack, Aoba grabbed and threatened the neighbour over an apparent misunderstanding. It started when Aoba began pounding on the wall to complain about noise, the neighbour said.
When the neighbour went to Aoba's front door to tell him the noise was coming from another unit, he heard a loud wail inside the apartment and then the door opened. "When he came out of his apartment, his eyes were bloodshot, and he started yelling at me to my face to shut up," the neighbour said. "He grabbed me by the collar and started pulling my hair. It was terrifying."
After the Kyoto attack, Aoba told police he had done it because the studio had plagiarised his novel, Kyodo news reported. Kyoto Animation is well known in Japan and abroad for its series and movies, including Violet Evergarden, which has been screened on Netflix.
Aoba had lived in the Omiya apartment for about three years, the neighbour said. Japanese media said he had moved in at some point following his release from prison for robbing a convenience store east of Tokyo in 2012. He had also received care for mental illness, NHK said.
Residents in the area said they were shocked by the news of the arson.
"I've lived here all my life, and until very recently, this area has never had any incidents of violence, or talk of violent people living in the neighbourhood," said an engineer in his 20s, who was going to visit his parents who live near Aoba's apartment. "It's unsettling."