AKB48 (pronounced A.K.B. Forty-Eight) is a Japanese idol girl group named after the Akihabara (Akiba for short) area in Tokyo, where the group's theater is located. AKB48's producer, Yasushi Akimoto, wanted to form a girl group with its own theater and performing daily so fans could always see them live (which is not the case with usual pop groups giving occasional concerts and seen on television). This "idols you can meet" concept includes teams which can rotate performances and perform simultaneously at several events and "handshake" events, where fans can meet group members. Akimoto has expanded the AKB48 concept to several girl groups in Mainland China, Japan, Indonesia, Thailand, Taiwan, Philippines, and Vietnam. AKB48 have been characterized as a social phenomenon. They are among the highest-earning musical acts in Japan, and are the fifth-best-selling girl group worldwide. For example, their 2012 sales from record and DVD/Blu-ray releases reached $226 million, earning the group the top spot in the 2012 artist ranking. As of April 2019, the group has sold over 60 million records, including over 6 million albums. At least 35 AKB48's singles have topped the Oricon Weekly Singles Chart, with at least 30 singles selling over a million copies each, making the group the highest selling musical act in Japan in terms of singles sold. Their highest selling single, "Teacher Teacher", sold over 3 million in 2018 according to Billboard / Soundscan. Between 2010 and 2020, AKB48's singles have occupied at least the top two spots of the Oricon Yearly Singles Chart.