If demons appear, it must be summer. When the days turned hot and muggy in pre-modern Japan, people would tell each other stories of ghosts and yokai: a catch-all term for demons, monsters and shapeshifting creatures.
The storytellers probably did this for fun - and because of a belief that being frightened has a chilling effect on the body.
This tradition of scaring people to help them cool down has lasted to the present day, with haunted houses springing up in amusement parks and a whole host of supernatural-themed events taking place during summer.
For five days in August, humans can travel with creatures from the other world on board the the Yokai Densha, or Haunted Train - a special service that runs between central Kyoto and the scenic Arashiyama suburb on the Randen tram line.
Adults pay 200 yen (about S$2) each for the 20-minute trip. Children can travel for half that but supernatural passengers - defined on the company's website as "anyone who at first glance looks like a yokai" - can ride for just 50 yen (about 50 cents).
That may explain the strangeness in the ticket queue.
I spot demon masks, a fox woman and someone carrying a small skeleton.
The boy in front of me is accompanied by his mother, who holds a plastic case and a tape dispenser.
"Where do you want these?" she says.
She pulls out a stack of home-made paper eyes, coloured inexpertly with crayon.
The woman helps him stick the eyes to his hands and back.
An employee at the station is coming down the line. "Ticket sales will begin shortly," she calls.
"Passengers intending to travel as yokai, please assume your demon form now."
People in the queue begin slipping on masks; a girl drapes what looks like a tablecloth over her head. The boy in front of me sticks two more paper eyes on himself.
The railway noises in the distance rumble closer. A voice over the PA system announces: "The Haunted Train is approaching. For your safety, please stand behind the yellow line. The Haunted Train is approaching."