Shinichi and Ran are riding a bus in Beika when Ran is suddenly touched on her butt by molester Osamu Sawada. After chasing the molester, Shinichi and Ran come across a case at the Beika Residence apartments where Katsuyo Miyano's respirator ceased working and she lies between life and death. Is Makoto Yamashita responsible for the respirator trouble through neglect or is there more to this case, and what does Sawada's obsession with Yukari Miyano's black underwear have to do with anything?