AKB48 is named after Akihabara (Akiba for short), the area in Tokyo where, on the 8th floor of a Don Quijote store, the band's own theater is located. Akimoto's idea, later advertised as "idols you can meet", was to create a theater-based idol group whose fans could see the girls live daily. AKB48 still performs at the theater every day, although, due to great demand, tickets are now distributed only via a lottery.

AKB48 holds the Guinness World Record for being the world's "largest pop group". Currently, it consists of four teams: Team A,Team K, and Team B with 16 members each and Team 4 with 11 members, summing up to a total of 59 members as of September 2, 2011. Additionally, there are a number of aspiring members, who are called "kenkyūsei" ("trainees"). Each team produces a new own concert show each theatrical season.

Since 2005, when AKB48 was founded, Yasushi Akimoto created several more groups: SKE48, based at a theater in the Sakae area of Nagoya, SDN48, which is intended to have a more mature image, and NMB48.

Another concept, first put into action in 2009, is general elections in which fans vote to determine the member line-up who will participate in the recording of AKB48's next single. In the last election, held in June–July 2011, where over a million votes were cast, 40 girls were chosen out of 152 members in AKB48, SKE48, SDN48, and NMB48. In 2010, a new and inventive selection method appeared: the girls competed against each other in a rock-paper-scissors tournament for being on a single. The second tournament took place on September 20, 2011.

On December 8, 2005, the group debuted in the theater with only 20 girls, later known as Team A. A new audition was announced, this audition was held in cooperation with Japanese telecom company NTT DoCoMo. It was the first audition ever where the applicants had to send in their audition video with their mobile phones. 19 of the 11,892 applicants were chosen to join AKB48, but in the end only 18 girls joined the group to become Team K in April 2006.In July 2005, Yasushi Akimoto held an audition for a new theater-based idol girl group. Of the 7,924 girls that applied, 45 passed the first round of auditions, detailed screening of the application documents. Finally, only 24 girls were chosen to be in the group.

In January 2006, Akimoto let Mariko Shinoda join the group without passing audition, after she won a popularity vote by fans, although she was working as a waitress at the Theater Cafe after she failed to attend the first audition back then.

AKB48 released its debut single "Sakura no Hanabiratachi" in February 2006, which made it to #10 on the Oricon weekly charts and sold 22,011 units in its first week - surprising for a group on an indie label.

On March 1 AKB48 released their first photo book, Micchaku! "AKB48" ~Shashinshuu Vol.1 the DEBUT. On March 31 Yuki Usami graduates, becoming the first member to do so.

On June 7 they release their second indies single "Skirt, Hirari", and sang their song first time on TV programs, Music Station and Music Fighter, on June 9, and on the 17th Ayako Uemura graduates.From April 1, 2006, Team K begins performances at the theater.

In August 2006, they signed a major label contract with DefStar Records, a part of Sony Music Entertainment. Their first single under DefStar Records, "Aitakatta", was released on October 25, 2006 and got to #12 on the Oricon weekly single charts. "Aitakatta" sold 25,544 copies, during the first 6 weeks charted on Oricon.

On November 3 & 4, 2006, AKB48 performs in their first concert AKB48 First Concert "Aitakatta ~Hashira wa Nai ze!~ at Nippon Seinenkan in Sendagaya, Shinjuku. In December 2006, the first change was made to the three teams; transferring Kazumi Urano, Shiho Watanabe, and Natsumi Hirajima from Team A to Team B as supporting members. Ayumi Orii graduated from the group shortly after this, though appeared in the unit Crayon Friends from AKB48 after her graduation.

On January 31, 2007, AKB48's fourth single (second on DefStar Records) "Seifuku ga Jama wo Suru" was released, reaching 7 on Oricon charts. There has been speculation that the PV and lyrics to this song are an allusion to enjo kōsai—voluntary underage prostitution—though this has not been confirmed.

On March 2, AKB48's second photo book AKB48 JUMP&CRY, which photos were taken by Kishin Shinoyama on February 3, was released.

Their next single, "Keibetsu Shiteita Aijō", which was released on March 18, featured a theme of school bullying and suicide throughout the lyrics and PV and reached 8 on the Oricon charts. AKB48's second concert tour, AKB48 Haru no Chotto dake Zenkoku Tour ~Madamada daze AKB48!~ began on March 10.

In April 2007, Team B was added to AKB48's official website; albeit with five fewer members than had originally been announced. This brought the group's numbers down from 53 to 48 - the first time since its creation that the member total reflected the group's name. Members Yū Imai, Michiru Hoshino, and Ayana Takada graduated at roughly the same time during June 2007. However, Takada was the only one of these to appear in the PV to the group's sixth single "Bingo!", which was released on July 18, 2007.

In October and November respectively, Shiho Watanabe and Kayano Masuyama graduated.

On December 31, 2007, 43 members of AKB48 appeared on the 58th Annual Kōhaku Uta Gassen for the first time. They sang as part of the Akihabara performance, with Leah Dizon andShōko Nakagawa following them. They became the largest number of people in a single group to be on stage at one time.

AKB48 released their first studio album on New Year's Day, titled Set List: Greatest Songs 2006–2007. Their seventh single Romance, Irane is released, reaching number 6 on the Oricon charts.

On February 27, 2008, AKB48 released their tenth single, titled "Sakura no Hanabiratachi 2008". At the time of the release of their debut single "Sakura no Hanabiratachi", there was only Team A in AKB48. This 10th single features ten members from Team A, along with six selected members from Team K, and five selected members from Team B making it the 2008 version. It was planned that people who collected 44 posters of the single CD would be invited to a special event, but this act was suspected as the violation of the antitrust law and was eventually cancelled by DefStar Records. In August 2008, they moved from DefStar Records of Sony Music Entertainment to King Records.

In August 2008, Ayaka Kikuchi was fired, though she was later rehired through another audition.

On October 22, 2008, the single "Ōgoe Diamond" was released from newly contracted King Records on the "You, Be Cool!" label, and finished the first week at number three in the Oricon charts. It was AKB48's first single that reached top three of the chart.

On November 3, 2008, Rina Nakanishi, Hitomi Komatani, Tomomi Ohe, Risa Narita, and Tojima Hana graduated.

On February 11, Reina Noguchi, Yuki Matsuoka and Nozomi Kawasaki graduated.

AKB48 released their 11th single, "10nen Zakura", on March 4, 2009. The single reached number three on the Oricon charts in the first week and eventually became the first single for them to sell over 100,000 copies on the Oricon charts.

On April 26, Mai Oshima and Kaoru Hayano graduated. On May 24, Risa Naruse graduated.

AKB48 Team A became the honour guest for the Japan Expo in Paris between July 2 to 5, 2009, and featured English-lyric version of "Ōgoe Diamond" first time.

AKB48's 12th single, "Namida Surprise!", was released on June 24, the single include handshaking event ticket and a voting card (with a serial number) for their next single. "Namida Surprise!" sold 104,180 copies in the initial week on the Oricon charts.

The 13th single, "Iiwake Maybe", released on August 26, 2009, surprisingly outsold SMAP on its first day, taking the 1st place in the Oricon Daily Singles Chart, but eventually ranked 2nd for the week.

AKB48 had a US debut concert at Webster Hall in New York on September 27, 2009.

In October 2009, their three singles "10nen Zakura", "Namida Surprise!" and "Iiwake Maybe" were certified Gold by the Recording Industry Association of Japan at the same time for each shipments of 100,000 copies by September. Their 14th single, "River", was released on October 21, 2009, and hit number 1 on Oricon upon its debut.

On 23 October the band represented Japan and performed at the 7th Asia Song Festival, organised by Korea Foundation for International Culture Exchange, at the Seoul Olympic Stadium. On October 27, 2010 AKB48's new single "Beginner" was released. In only the first week, the 18th single sold 826,989 copies making it the highest first week sales for AKB48, as well as highest first week sales ever for a female idol group single. As of February 2011 the single has sold over 1,010,000 copies. At the end of October Mayu Watanabe appeared on the cover of the December issue of UP to boy magazine together with Airi Suzuki from °C-ute. That was the first gravure collaboration between Hello! Project and AKB48. At AKB48's concert at the Yoyogi National Gymnasium on a Sunday in July 2010, it was announced that Team K member Erena Ono would be graduating from AKB48 to study acting abroad. Erena graduated from AKB48 on September 27, 2010 in a Team K theater performance.

In November 2010, AKB48 performed in Russia for the first time. A 12-member team gave a concert on November 20 at the Japanese Pop Culture Festival which took place in Moscow. Also in November 2010, AKB48 performed in the Cool Japan Night in Singapore as part of the Anime Festival Asia X. This is followed by a 2nd performance also in Singapore at the Singapore Toy Games & Comics Convention.

The first single of the year, named "Sakura no Ki ni Narō", was released on February 16. Upon the first day of release, AKB48 sold 655,000 copies of their single, beating their previous top record (568,000 copies of "Beginner"). The single sold 942,479 copies in its first week, AKB48's highest record.

In February, it was announced that Yūki Kanazawa and Manami Oku would be graduating from the group.

Their third studio album, named Koko ni Ita Koto (ここにいたこと^?), was announced on 21 February 2011. This is their first original album (as opposed to collections of previously released singles), and it contains 11 new songs that were never released before, including the title track Koko ni Ita Koto. It was scheduled to be released in Japan on 6 April 2011.

On March 12, 2011 it was also announced on their blog that the AKB Theater would close due to the 2011 Tohoku earthquake and tsunami, and all public events were cancelled until further notice. Two days later, it was announced on their official blog that their concert Takamina ni tsuite ikimasu (たかみなについて行きます^?, lit. "(We) will follow Takamina"), scheduled to be held on March 25–27 at Yokohama Arena, would be cancelled. Bank accounts had been opened to raise donations for earthquake and tsunami relief, as part of their project named "Dareka no Tame ni" (誰かのために lit. "For someone's sake"^?). Under this project, they used the Yokohama Arena for their 2-day charity events starting on 26 March 2011 instead. 12 of their main members attended Okinawa International Movie Festival on the same day for the same purpose. Three days later, it was announced that ¥500 million will be donated by AKB48and their sister groups: SKE48, SDN48 and NMB48, and their producer Yasushi Akimoto to these bank accounts. On the same day, the postponement of the release of their new album,Koko ni Ita Koto (ここにいたこと^?) was announced. Part of the proceeds from the sales of the album will be donated to the victims of this disaster. It was also announced that the group will hold a senbatsu election to determine the participating members for their 22nd single. On April 1, they also released a single, "Dareka no Tame ni (What can I do for someone?)" (誰かのために -What can I do for someone?-^?) through the Recochoku website as a digital download, and will donate all profits for earthquake and tsunami relief. Dareka no Tame ni was originally recorded on a live album released in 2007.

On April 8, Manami Oku graduated after performing at a Team B stage on the same day.

On May 1, a new AKB48 unit named HKT48 was announced. It will be based in Fukuoka in Kyushu, and their theater will be established in the Hawks Town Mall of Fukuoka’s Chuo ward.

AKB48 released their 21st singles album entitled "Everyday, Kachūsha" on 25 May 2011. On its release day 942,475 copies were sold and 1,333,969 copies in the first week making it the highest first-week single sales record in Japan to that date. Later, on June 7, AKB48 announced a new team titled "Team 4" ahead of their nationwide tour concerts in Japan. The team was formed of ten members, with six more members to be added later to complete the 16-member team. This also marked 'Team Kenkyuusei' losing the 'Team' from their name.The AKB48 staff blog announced that the trainees Nau Yamaguchi and Sara Ushikobu will leave the group for undisclosed reasons. They will perform their last event as members on June 19.

On June 11, 2011, It was announced at a handshake event that Aimi Eguchi, a girl who had supposedly auditioned for NMB48, would be joining AKB48 as a trainee. It was later revealed that Aimi Eguchi was not a real person, and had been created to promote the Glico product Ice no Mi.

Oricon announced on 22 June 2011 that AKB48 had the strongest album sales showing for the first half of 2011 in their sales ranking. They had the only two million-selling singlesEveryday, Kachūsha and "Sakura no Ki ni Narō", which ranked as the best and second-best selling singles respectively. For the survey period between 27 December 2010 and 20 June 2011, AKB48 garnered ¥6.66 billion in total sales of all their merchandise.

In an announcement made on 28 June 2011, AKB48's producer Yasushi Akimoto revealed that he will be creating a group to become AKB48's "official rival". The group will be calledNogizaka46 (乃木坂46^?) and will debut with approximately 20 members. Yasushi Akimoto revealed that he teamed up with Sony Music Japan to produce this new group, whose auditions for members will start later this year.

AKB48 released their 23rd major single(25th overall), Kaze wa Fuiteiru on 26 October 2011. The single sold 1,045,937 copies on the first day of release and set a new record for the first day sales of AKB48 singles. They subsequently released their 24th major single Ue Kara Mariko on 7 December 2011. This single sold 1.199 million copies in the first week after its release.

For the year of 2011, AKB48 topped 7 of the 16 Oricon's rankings. These rankings includes: Total sales by an artist, Copies sold for a single, Total sales for a single, Total sales by an artist (for singles), Copies sold for a music Blu-ray disc, Total sales for a music Blu-ray disc and Total sales by an artist (for Blu-rays discs). In addition, it was also announced that the group broke the all-time records for the most singles selling over 1 million copies in a year, the best-selling single by a female group and the highest-earning female group. AKB48 won the 53rd Japan Record Award for their song Flying Get.

AKB48 will receive their first television anime series. This anime series is directed by Yoshimasa Hiraike, while it is planned and supervised by AKB48 producer Yasushi AkimotoThe group will release their 25th single, "GIVE ME FIVE!", on 15 February 2012.