From Nippon.com; February 15, 2019
Railway passengers endure stifling trains and other miseries on their crowded commutes, but the behavior that rankles them the most is people wearing backpacks. According to an annual survey on train and station manners by the Japan Private Railway Association, a group of 73 railway companies nationwide, train passengers are most annoyed by how people carry or place their bags on trains, with backpacks or shoulder bags causing the greatest irritation. The issue of noisy conversations and revelry placed a close second in the survey, which has been conducted since 1999, followed by how people sit in third spot.