au, or au by KDDI, is a Japanese mobile phone operator. au is a brand marketed by KDDI in the main islands of Japan and by Okinawa Cellular in Okinawa for their mobile cellular services. au is the second-largest wireless carrier in Japan, with 60.398 million subscribers as of March 2021.[1]
Naming
According to the brand creator, the name 'au' is based on the Japanese verbs for 'meet' (会う) and 'unite' (合う) (both pronounced 'au').[2] However, KDDI explains that au comes from two letters which stand for few words. 'A' is for access, always and amenity, and 'U' is for unique, universal and user. There is also a phrase, 'access to u(you)' that goes along the brand name.[3]
History
The network that would eventually become au was originally set up as two networks: DDI and IDO.