Underwear-maker Masayuki Tsuchiya says he had toyed with the idea of making bras for men for about seven years, but there was always one sticking point: What function could they possibly perform?

"Women's bras make breasts look larger or stop them from sagging," the entrepreneur explained. For men's bras to succeed, he reasoned, surely they too would need some clear purpose.

Early last year the answer occurred to him. The few male customers who had called his Tokyo-based company, WishRoom, inquiring about bras did not seem interested in making their pectoral muscles look bigger, or improving their posture. "They said wearing a bra just made them feel more calm, relaxed and revived," Tsuchiya said. From a man's perspective, it turned out, the sole and sufficient purpose of a bra was psychological.