The operator of the Seven-Eleven convenience stores in Japan has sent a formal warning to a franchise owner who filed a request to temporarily shorten operating hours due to a labor shortage, the owner said Friday.Seven-Eleven Japan Co. has been under scrutiny over its stance toward franchise owners who face difficulty finding employees. The latest revelation comes only months after the company pledged to review its 24-hour operating policy and respond more flexibly to the needs of each outlet.The franchise owner in Gunma Prefecture, eastern Japan, received the letter Friday from Seven-Elev…READ FULL ARTICLE