In Tokyo in the near future, the rich and big companies lived in the sky to avoid disasters and epidemics. The poor, on the other hand, lived underground. NOUNAI Senri, who lives underground, joins RUOWA, a large pharmaceutical company, to cure his sister Mari's incurable disease. NOUNAI Senri takes RUOWA Metal, a drug that turns his muscles into metal, which has the side effect that his brain cells become like sand and die if he continues to take it. He suffers from this side effect and his body becomes weak. At the same time, however, he was also in the business of killing people who were suffering from the same side effects.