Due to serious burns sustained during the incident, Aoba was transferred to a university hospital in [[Osaka]] for further treatment, where he received necessary [[skin graft]] surgery.<ref name="nhk_20190720_aoba1" /><ref name="nhk_20190720_aoba2" /> On 5 September 2019, it was reported that his injuries were no longer considered life-threatening,<ref name="fnnprime_20190905_suspectrecovery"/> but he was still being treated in an ICU and required [[respiratory assistance]] from a [[ventilator]].<ref name="ks_20190917"/> Aoba regained speech on 18 September and began rehabilitation by 8 October, being able to sit up on a wheelchair and hold short conversations. The police obtained a warrant for his arrest, but were required to await confirmation from doctors that Aoba could withstand confinement.<ref name="kyodo_20190918_speech"/><ref name="kyodo_20191008_rehab"/>
On 14 November 2019, he was moved to another hospital in Kyoto City for final rehabilitation.<ref name="jiji_20191114_suspecthospitaltransfer"/> He recovered from most of his injuries and acknowledged responsibility for the attack. He expressed feelings of remorse and gratitude towards the hospital staff, who he said treated him better than anyone had ever done in his life.<ref name="ks_20191115_hospitalkindness"/> On the other hand, he told police that he lit the fire because Kyoto Animation had stolen his novel, and that he expected to get the death penalty.<ref name="jt_20191111_questioning"/> Most of Aoba's burned skin was replaced with experimental artificial skin as the victims were prioritized to receive donor human skin first.<ref name="sky_20191127_arsonskingraft"/><ref name="telegraph_20191127_experimentalskin"/> The use of artificial skin on such extensive burns is the first case in Japan.<ref name="sky_20191127_arsonskingraft" /><ref name="telegraph_20191127_experimentalskin"/>
By January 2020, Aoba remained hospitalized, and was unable to stand or eat unassisted.<ref name="nhk_20200118_suspectstatus"/> On 27 May 2020, Aoba was judged to have sufficiently recovered from his burn injuries, and he was formally arrested on suspicion of murder and other charges.<ref name="reuters_20200527_suspectarrest"/><ref name="bbc_20200527_suspectcharged"/> He was indicted on 16 December 2020 on murder and other charges.<ref name="asahi_20201216_murderchargefiled"/><ref name="variety_20201216_murderchargefiled"/>
Due to serious burns sustained during the incident, Aoba was transferred to a university hospital in [[Osaka]] for further treatment, where he received necessary [[skin graft]] surgery.<ref name="nhk_20190720_aoba1" /><ref name="nhk_20190720_aoba2" /> On 5 September 2019, it was reported that his injuries were no longer considered life-threatening,<ref name="fnnprime_20190905_suspectrecovery"/> but he was still being treated in an ICU and required [[respiratory assistance]] from a [[ventilator]].<ref name="ks_20190917"/> Aoba regained speech on 18 September and began rehabilitation by 8 October, being able to sit up on a wheelchair and hold short conversations. The police obtained a warrant for his arrest, but were required to await confirmation from doctors that Aoba could withstand confinement.<ref name="kyodo_20190918_speech"/><ref name="kyodo_20191008_rehab"/>
On 14 November 2019, he was moved to another hospital in Kyoto City for final rehabilitation.<ref name="jiji_20191114_suspecthospitaltransfer"/> He recovered from most of his injuries and acknowledged responsibility for the attack. He expressed feelings of remorse and gratitude towards the hospital staff, who he said treated him better than anyone had ever done in his life.<ref name="ks_20191115_hospitalkindness"/> On the other hand, he told police that he lit the fire because Kyoto Animation had stolen his novel, and that he expected to get the death penalty.<ref name="jt_20191111_questioning"/> Most of Aoba's burned skin was replaced with experimental artificial skin as the victims were prioritized to receive donor human skin first.<ref name="sky_20191127_arsonskingraft"/><ref name="telegraph_20191127_experimentalskin"/> The use of artificial skin on such extensive burns is the first case in Japan.<ref name="sky_20191127_arsonskingraft" /><ref name="telegraph_20191127_experimentalskin"/>
By January 2020, Aoba remained hospitalized, and was unable to stand or eat unassisted.<ref name="nhk_20200118_suspectstatus"/> On 27 May 2020, Aoba was judged to have sufficiently recovered from his burn injuries, and he was formally arrested on suspicion of murder and other charges.<ref name="reuters_20200527_suspectarrest"/><ref name="bbc_20200527_suspectcharged"/> He was indicted on 16 December 2020 on murder and other charges.<ref name="asahi_20201216_murderchargefiled"/><ref name="variety_20201216_murderchargefiled"/>