There is a sign stating "DO NOT BLOW CONCH SHELL HORNS" on a promenade along the outer moat of Nijo-jo Castle, World Heritage in Nakagyo Ward, Kyoto. "Why conch shell horns?" is now a hot topic among nearby residents and the Internet.
　
The sign is located on the promenade at the north side of the castle precincts. Last September, a neighbor filed a complaint with the city government office in charge of administration of Nijo-jo Castle, saying, "Someone blows a conch shell horn at the promenade in the early morning on weekends and holidays. It is disturbing." Having received the same complaint from other neighbors, an office staff immediately hung signs saying, "DO NOT PLAY MUSICAL INSTRUMENTS" and "DO NOT TALK LOUDLY" at the entrance of the promenade.

Nevertheless, the complaints about hearing a conch horn didn't stop. When the staff consulted with the Nakagyo Police Station, the latter advised, "You could improve the content of the sign." They also said, "Probably, the horn player does not realize that the prohibition is for him." The following month, the staff hung a sign that said clearly, "DO NOT BLOW CONCH SHELL HORNS," at the east end of the promenade, where the neighbors said they had seen the horn player. Since then, no complaints have been made.

What really happened still remains a mystery, as no officer has heard the horn or seen the player because the problem happened before their working hours. Since the beginning of April, the sign has become a hot topic in Social Networking Services (SNS) and other sites. A female resident who walks her dog on the promenade, laughed, "My mom and I were a bit excited to see such an overly specific ban."

The person in charge at the office said, "I think people who don't know the whole story will wonder what the sign is for," and added, "It's not only conch shell horns. Please refrain from anything that may be annoying to area residents."