The narrator introduces us to a young man named sideburns, who has come to meet his friend, akatsuki, on a famous bridge in the city of San Francisco. The two of them have been waiting on the bridge for two hours, and the narrator wants to give them a tour of the city. He tells the young man that he is the city's pro-tector, which means that he's in charge of all things city-related. The young man asks if he can give him a ride, but the narrator tells him that he can't yet give a ride without an instructor, so they'll have to wait for someone else to come pick them up. He also tells the man that the city is famous for its floating island, and that it's his job to control the island's orbit as though he were on the island. The narrator then tells him to sit down on the wall of the bridge so he can relax. He says that humans are like animals, too, and humans are anxious when they're not around. He compares the old man to an animal who's anxious when its back is unprotected, and he wonders why people sigh when the bridge is in front of them. The bridge is named after the condemned prisoners who used to pass through it every time they went to the prison, he says. He doesn't know why, but he does know that it makes people sigh.