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 keeps taking it. Can he recover from the side effect?