Advertisement boards for the Kyoto Animation are displayed on the railway station near the studios' building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Firefighters work at the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Smoke billows from a fire at the Kyoto Animation studio in Kyoto, Japan July 18, 2019, in this still image obtained from a social media video. INSTAGRAM / @XRAY_RAIX via REUTERS.

A man prays next to the flowers dedicated to the victims of the fire, near the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Kyoto Animation building which was torched by arson attack is seen in Kyoto, Japan, July 18, 2019.

Firefighters check the torched Kyoto Animation building in Kyoto, Japan, July 19, 2019.

An aerial view shows firefighters battling the fires at the site where a man started a fire after spraying a liquid, at a three-story studio of Kyoto Animation Co. in Kyoto, western Japan, in this photo taken by Kyodo July 18, 2019. Mandatory credit Kyodo/via REUTERS

Rescue workers carry injured people from the three-story Kyoto Animation building which was torched in Kyoto, western Japan, in this photo taken by Kyodo July 18, 2019. Mandatory credit Kyodo/via REUTERS

Kyoto Animation building which was torched by arson attack is seen in Kyoto, Japan, July 19, 2019.

A firefighter is seen near the roof of the torched Kyoto Animation building in Kyoto, Japan, July 19, 2019.

A man prays outside the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

A man prays outside the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Firefighters conduct an investigation at the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019. REUTERS/Kim Kyung-Hoon - RC16F9A490B0

A man prays for the victims of the arson attack in front of the torched Kyoto Animation building n Kyoto, Japan, July 19, 2019.

A window of Kyoto Animation building which was torched by arson attack is seen in Kyoto, Japan, July 19, 2019. Image for illustrative purposes.

An aerial view shows smoke and flame rise from the three-story Kyoto Animation building which was torched in Kyoto, western Japan, in this photo taken by Kyodo July 18, 2019. Mandatory credit Kyodo/via REUTERS

Flowers are placed in front of the torched Kyoto Animation building to mourn the victims of the arson attack in Kyoto, Japan, July 19, 2019.

A police officer stands guard at a location where the suspected arsonist was detained, near the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

An aerial view shows firefighters battling fires at the site where a man started a fire after spraying a liquid at a three-story studio of Kyoto Animation Co. in Kyoto, western Japan, in this photo taken by Kyodo, July 18, 2019. Mandatory credit Kyodo/via REUTERS

A fan of Kyoto Animation cries as she visits the area near the studios' building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Firefighters conduct an investigation at the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Volunteer fire corps members stand guard in front of the Kyoto Animation building which was torched by arson attack in Kyoto, Japan, July 18, 2019.

Kyoto Animation building which was torched by arson attack is seen in Kyoto, Japan, July 18, 2019.

A policeman stands guard in front of the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

A man takes photos of the torched Kyoto Animation building after an arson attack in Kyoto, Japan, July 19, 2019.

A fan of Kyoto Animation cries as she visits the area near the studios' building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Advertisement boards for the Kyoto Animation are displayed on the railway station near the studios' building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Flowers and a drawing with anime characters dedicated to the victims of the fire are seen left outside the Kyoto Animation building which was torched by arson attack, in Kyoto, Japan, July 19, 2019.

Flowers are placed near the Kyoto Animation building which was torched by arson attack in Kyoto, Japan, July 18, 2019.