SDN48 (short for Saturday Night 48) was a Japanese idol girl group created and produced by Yasushi Akimoto based in Akihabara, Tokyo. SDN48 was created based on an "adult idol" concept. Former AKB48 member Kayo Noro was chosen as the captain of the group. In November 2010, the group made their major label debut with "GAGAGA". On October 15, 2011, it was announced that all SDN48 members will graduate from the group during a farewell concert on March 31, 2012. 2008-2009: Formation In 2008, AKB48 producer Yasushi Akimoto decided to create a "Saturday Night 48" show, based on the concept of an "adult idol" and would perform every Saturday at 10 pm. The shows are restricted fans age 18 and older. He also wanted to differentiate from AKB48's usual uniforms with more sexy attire. In July 2009, Two AKB48 members, Megumi Ohori and Kayo Noro were chosen as the first two members of the group. At the same time auditions were held to find other members. SDN48 debut stage 誘惑のガーター was held on July 25. At the end of AKB48's three day Nippon Budokan concert the teams were reshuffled leading to the removal of Kayo Noro, Megumi Ohori, Yukari Sato, and Kazumi Urano, leaving them to solely focus on SDN48 activities. Noro was also made the captain of the group. It was announced on September 27, 2009, that Yuki Iwata who was a under (understudy) departed from the group due to health reasons. Two months later, Eiko Maeda was transferred from sister group SKE48 to SDN48. Upon joining the group Maeda changed her stage name to Machiko Tezuka. 2010: Major-label debut During their first year anniversary concert, Noro announced to the audience that SDN48 would debut under Universal Music in the fall. It was also suggested by the group that they will be getting rid of the age restriction in the future. Through their TV show, すっぽんの女たち, SDN48 held a senbatsu election to determine top twelve members were going to participate in their debut single. Former AKB48 member Megumi Ohori won No. 1 and was given the center position. It was also revealed that the single would be titled "GAGAGA" and would be released on November 24, 2010. On September 30, 2nd generation member, Sakura Fukuyama —who ranked in the senbatsu— announced through her blog that she would be leaving the group due to health problems. Chinese member Chen Qu was chosen as Fukuyama replacement.