KDDI is a telecommunications company. Along with its affiliates, Co. operates in four principal business segments: personal, value, business, and global. Co. is engaged in the sale of mobile handset; and the provision of mobile telecommunication services under "au" brand name, Internet contents, settlement service, and electronic money service for individual customers. Co. offers information and communication technology ("ICT") solution services and data center services for domestic corporate customers, overseas companies and individual customers. Co. is also involved in the call center business, the research and technological development, and the telecommunication facilities maintenance.

Nippon Telegraph and Telephone and its subsidiaries conduct the following main business activities: regional communications (domestic intra-prefectural communication services and incidental services), principally operated by Nippon Telegraph and Telephone East Corporation and Nippon Telegraph and Telephone West Corporation; long-distance and international communications (domestic inter-prefectural communication services, international communication services and incidental services), principally operated by NTT Communications Corporation; mobile communications, principally operated by NTT DOCOMO, Inc.; and data communications, principally operated by NTT DATA CORPORATION.

Rakuten is mainly engaged in the Internet-related business. Along with its affiliates, Co. operates in two business segments. The Internet Services segment is engaged in the operation of electronic commerce sites, including an Internet shopping mall "Rakuten Ichiba," an online cash back site, a travel booking site, portal sites and digital contents sites; the sale of advertising on Co.'s sites; the provision of messaging and communication services; and the management of a professional baseball team "Tohoku Rakuten Golden Eagles." FinTech segment is engaged in the provision of Internet banking services and online securities trading services, and the credit card and life insurance businesses.

Yahoo Japan is engaged in the provision of Internet advertising and e-commerce services. Media Business segment provides marketing and advertising services including paid search, display, in-feed video advertising and other advertising-related services for corporations; and Yahoo! News and media-related services. Commerce Business segment provides e-commerce related services including YAHUOKU! (net auction site), Yahoo! Shopping, ASKUL, LOHACO and other shopping websites; membership services including Yahoo! Premium, Yahoo! BB and other services; and financial and payment-related services including credit card, e-money, foreign exchange margin trading and other related services.