This case study discusses about a US membership wholesale club Costco’s entry into Japan in 1999 and how they have grown their wholesale business in Japan to the successful example it is today. A reader of this case study can learn how to utilize the Costco Japan practice to enter the global market despite the differences in business customs and cultures, as well as how to maintain the corporate sustainability when expanding your business to overseas. The Japanese retail market is fragmented and it is hard to penetrate especially for a foreign retailer. While both domestic and international players in the membership wholesale club and supercenter industry have failed and pulled their businesses out of Japan, what are the Costco Japan’s secrets of keeping the operation profitable and sustainable? A reader can discover how Costco Japan differentiated themselves in order to thrive in Japan. This case can be used in a class for undergraduate students or MBA students. It is a perfect gateway into the world of global business practice for those who have less experience in a corporate environment. This Costco Japan’s practice can be taught in different and more focused angles such as consumer behaviors, business models and strategies, managing in a different cultural environment, creative thinking, and entering a new and competitive market for those who have extensive experience in the global business.