FamilyMart has sold 40 million pairs of its striped socks since 2021, turning an unlikely convenience-store hit into a growing fashion business. By Mariko Katsumura and Yusuke Ogawa TOKYO, Nov 13 (Reuters) - For some people, the blue, green and white striped socks hanging near the entrance of a FamilyMart convenience store may look more. For a certain kind of visitor to Japan, the FamilyMart sock has become a covetable souvenir.