China's fire brigade confirmed that a person has died and 12 people were found with "no essential signs" inside the building belonging to Kyoto Animation Co. In Japan, deaths must be confirmed by a physician before publication.
The Kyoto police said a man poured out what appeared to be gasoline around Kyoto Animation Studio and set it on fire. The suspect, described by the police as his 40s, has been taken into custody.
Firefighters said that another 38 people were injured, of which ten believed they were in a serious condition.
The fire broke out at 10:30 am local time on Thursday (9:30 PMET) and the police said a resident reported hearing a sound as an explosion coming from the studio.
About 48 fire engines have been sent to the area and are currently trying to get the fire under control.
Films from the scene show thick smoke that pops out of the building with four floors, because firefighters work to dampen the flames.
The building is located in a residential area several kilometers south of Kyoto Station.
This is a developing story.