More than just convenience, Japan’s quick-stop stores offer some helpful lessons on good product design. — Visitors to Japan are often surprised by the convenience stores (コンビニエンスストア, konbiniensu sutoa), locally often shortened to konbini (コンビニ). Whether you’ve popped into a 7-Eleven, Lawson, FamilyMart, Daily Yamazaki, MiniStop, or one of the smaller chains, you’re in for a treat. When you walk into the store, the products on…