TOKYO -- I followed the instructions of the watchful cashier and took off my shoes, sanitized my hands, placed my bag in a locker and dangled an ID card ("customer #18") from a lanyard around my neck. The cashier then gave me a once over and a shallow bow, and I padded quietly into the sitting room of the cafe.

"She's the prettiest girl we have at our cafe. Everybody wants to touch her, but we ask that customers...