Abstract
This paper describes the current status and challenges of Ai. At present, Ai is performed to prevent missing the crime or when medical-related death is suspected, but it is going to be a system which spreads out over the wider society in the future. Since die of the human occurs only once, Ai is also performed only once. It is possible in Japan, anyone can receive the Ai anywhere. There exist no other way other than Ai to investigate the cause of death fairly.