21g no Akari

Overview

"When we die, will we become electricity?" A heartwarming SF tale! A doctor, Duncan McDougall, once postulated a theory: "The soul weighs 21 grams." The theory, which had long been regarded as an empty fantasy with no basis in reality, has been proven true after several decades. Scientific and technological advances have revealed that the human body releases a small amount of an unknown gas after death. It turned out that this small amount of stable energy could be captured and used to generate electricity, revolutionizing human life... (Source: Mag Garden, translated)

Source: AniList