Tokyo in the near future. People were living in the sky to avoid epidemics and disasters. However, this is only the story of the rich, and those without money live underground. NOUNAI Senri, who lives underground, joins RUOWA, a large pharmaceutical company in the sky for the sake of his sister Mari, who cannot walk due to an incurable disease.
His sister Mari's leg cells swelled up and she could no longer walk. He cut out her increased cells and encouraged her.