In the near future in Tokyo, NOUNAI Senri's older sister Mari has an intractable disease that causes the cells in her legs to grow when her emotions run high, making it difficult for her to walk. The company's drug RUOWA Metal, which turns human muscles into metal, has eliminated the cells in Mari's legs that have increased in number. However, the drug had a side effect that caused the cells in the human brain to turn into sand and lead to death. What will happen to NOUNAI Senri, who has taken the drug?