The 1st to 3rd Generation are known as the Original Teams (1st Gen: Team A, 2nd Gen: Team K, 3rd Gen: Team B).
As more auditions were held later on, the successful candidates would take part of an in-training team of members. The trainees would work as "under members" that substituted for the official members in various activities, especially the theater performances. When any of the official members would graduate, one of the in-training members would be promoted to fill the space.
This group of trainees was called AKB48 SEED. The term was was dropped later on, and changed to Kenkyuusei (Research Students). After more generations were created, the Kenkyuuseis started to perform by their own stages in the theater. In 2009 Team Kenkyuusei was created, and the Kenkyuusei Selection was held for the first time. Since then, the Kenkyuuseis have even been part of senbatsu. In 2012, with the Tokyo Dome Team Shuffle, the Kenkyuuseis stopped replacing members on stage performances, just performing on their own Kenkyuusei Stage.
Currently, with exception of the 8th generation, all the generations have at least one member in the group. The members after the 9th generation are usually called the new generation members. Recently this term been used to describe the members after the 12th generation instead.
AKB48 had a total of 186 original members during all their 15 generations. As of May 2015, AKB48 has 129 members and 13 Kennin (including Team 8 Kennin).
AKB48 Auditions
1st Generation (Original Team A)
- Announced October 2005
Members (21): Itano Tomomi · Usami Yuki · Urano Kazumi · Ohe Tomomi · Oshima Mai · Orii Ayumi · Kawasaki Nozomi · Kojima Haruna · Komatani Hitomi · Sato Yukari · Takahashi Minami · Tojima Hana · Nakanishi Rina · Narita Risa · Hirajima Natsumi · Hoshino Michiru · Maeda Atsuko · Masuyama Kayano · Minegishi Minami · Watanabe Shiho | Shinoda Mariko (joined the group on 2006/1/22)
- Now on Team A (1): Kojima Haruna
- Now on Team K (1): Minegishi Minami
- Announced Graduation (1): Takahashi Minami
- Now graduated (18): Usami Yuki, Ohe Tomomi, Oshima Mai, Orii Ayumi, Kawasaki Nozomi, Komatani Hitomi, Tojima Hana, Nakanishi Rina, Narita Risa, Hirajima Natsumi, Hoshino Michiru, Masuyama Kayano, Watanabe Shiho, Maeda Atsuko, Urano Kazumi, Sato Yukari, Shinoda Mariko, Itano Tomomi
2nd Generation (Original Team K)
- Announced February 2006
Members (17): Akimoto Sayaka · Imai Yuu · Uemura Ayako · Umeda Ayaka · Oshima Yuko · Ohori Megumi · Oku Manami · Ono Erena · Kasai Tomomi · Kobayashi Kana · Sato Natsuki · Takada Ayana · Noro Kayo · Hayano Kaoru · Masuda Yuka · Matsubara Natsumi · Miyazawa Sae
- Now in Team B (1): Kobayashi Kana
- Now in NMB48 Team BII (1): Umeda Ayaka
- Now in SNH48 Team SII / SKE48 Team S (1): Miyazawa Sae
- Now graduated (13): Uemura Ayako, Imai Yuu, Takada Ayana, Hayano Kaoru, Ohori Megumi, Noro Kayo, Ono Erena, Oku Manami, Sato Natsuki, Masuda Yuka, Kasai Tomomi, Matsubara Natsumi, Akimoto Sayaka, Oshima Yuko
3rd Generation (Original Team B)
- Announced December 2006
Members (13): Inoue Naru · Ota Aika · Kashiwagi Yuki · Katayama Haruka · Kikuchi Ayaka · Saotome Miki · Tanabe Miku · Nakagawa Haruka · Nakaya Sayaka · Noguchi Reina · Matsuoka Yuki · Yonezawa Rumi · Watanabe Mayu
- Now in Team B (3): Kashiwagi Yuki, Tanabe Miku, Watanabe Mayu
- Now in HKT48 Team KIV (1): Ota Aika
- Now in JKT48 Team T (1): Nakagawa Haruka
- Now graduated (6): Inoue Naru, Noguchi Reina, Matsuoka Yuki, Yonezawa Rumi, Nakaya Sayaka, Katayama Haruka
- Former kenkyuusei (1): Saotome Miki
- Candidates (5): Iso Reina, Otsuka Aki, Sakata Ryo, Fujishima Mariachika, Hori Mina
- Kikuchi Ayaka, a Team B member, left the group but then returned on the 7th generation
AKB48 SEEDs / Research Students
4th Generation
- Announced May 2007
Members (18): Iinuma Yurina · Uriya Akane · Oya Shizuka · Kaneko Satomi · Kuramochi Asuka · Kozuka Rina · Saeki Mika · Sato Amina · Suzuki Nae · Deguchi Aki · Nakanishi Yuka · Nakata Chisato · Naruse Risa · Fujie Reina · Fujimoto Sara · Muranaka Satomi · Yoshioka Saki · Watanabe Marie
- Now in Team A (1): Oya Shizuka
- Now in Team B (2): Kuramochi Asuka, Nakata Chisato
- Now in NMB48 Team M (1): Fujie Reina
- Now Graduated (4): Naruse Risa, Saeki Mika, Sato Amina, Nakanishi Yuka
- Former Kenkyuusei (7): Iinuma Yurina, Uriya Akane, Kaneko Satomi, Kozuka Rina, Suzuki Nae, Yoshioka Saki, Watanabe Marie
- Muranaka Satomi left the group but then returned for the 8th generation
- Fujimoto Sara left the group but then returned for the 9th generation
- Saeki Mika left the group but then returned for Baito AKB
- Deguchi Aki left the group but then returned to SKE48
5th Generation
- Announced October 2007
Members (13): Arima Yuka · Ishida Haruka · Uchida Mayumi · Chikano Rina · Kitahara Rie · Kohara Haruka · Sashihara Rino · Tomita Mayu · Nakatsuka Tomomi · Nito Moeno · Hatayama Arisa · Miyazaki Miho · Yamada Mizuki
- Now in Team A (1):Miyazaki Miho
- Now in Team K (1): Ishida Haruka
- Now in HKT48 Team H (1): Sashihara Rino
- Now in NGT48 (1): Kitahara Rie
- Now in JKT48 Team KIII (1): Chikano Rina
- Announced Graduation (1):Uchida Mayumi
- Now Graduated (3): Kohara Haruka, Nito Moeno, Nakatsuka Tomomi
- Former Kenkyuusei (4): Arima Yuka, Tomita Mayu, Hatayama Arisa, Yamada Mizuki
6th Generation
- Announced April 2008
Members (4): Katano Yurie · Takajo Aki · Nishizawa Sara · Nonaka Misato
- Now on Team K (1): Takajo Aki
- Now graduated (1): Nonaka Misato
- Former Kenkyuuseis (2): Katano Yurie, Nishizawa Sara
7th Generation
- Announced December 2008
Members (11): Ishiguro Remi · Iwasa Misaki · Katono Mizuho · Kikuchi Ayaka · Komori Mika · Sato Sumire · Suzuki Shihori · Suzuki Mariya · Hayashi Ayano · Maeda Ami · Matsui Sakiko
- Now in Team A (1): Maeda Ami
- Now in Team B (1): Iwasa Misaki
- Now in SKE48 Team E (1): Sato Sumire
- Now in Team K / SNH48 Team SII (1): Suzuki Mariya
- Now graduated (3): Komori Mika, Kikuchi Ayaka, Matsui Sakiko
- Former Kenkyuusei (3): Katono Mizuho, Hayashi Ayano, Ishiguro Remi
- Suzuki Shihori left the group but then returned on the 11th generation
8th Generation
- Announced April 2009
Members (15): Asai Madoka · Ishii Ayaka · Ishibe Aya · Imai Yurie · Ueki Asaka · Kaku Grace · Komizu Nanami · Sakamoto Rio · Sano Yuriko · Sugiyama Miku · Tomite Ami · Nishikawa Nanami · Miki Nikoru · Muranaka Satomi · Komatsu Mizuki
- Former Kenkyuuseis (14): Asai Madoka, Ishii Ayaka, Ishibe Aya, Imai Yurie, Ueki Asaka, Kaku Grace, Komizu Nanami, Sakamoto Rio, Sano Yuriko, Sugiyama Miku, Tomite Ami, Nishikawa Nanami, Miki Nikoru, Muranaka Satomi, Komatsu Mizuki
- Nishikawa Nanami left the group but returned as part of Nogizaka46's 2nd Generation
9th Generation
- Announced September 2009
Members (14): Ishiguro Atsuki · Ito Ayaka · Oba Mina · Kinumoto Momoko · Shimazaki Haruka · Shimada Haruka · Takamatsu Eri · Takeuchi Miyu · Nagao Mariya · Nakamura Mariko · Fujimoto Sara · Mori Anna · Yamauchi Suzuran · Yokoyama Yui
- Now on Team A (3): Shimazaki Haruka, Nakamura Mariko, Yokoyama Yui
- Now on Team K (2): Shimada Haruka, Nagao Mariya
- Now on Team B (1): Takeuchi Miyu
- Now on SKE48 Team S (2): Yamauchi Suzuran
- Now on SKE48 Team KII (1): Oba Mina
- Now Graduated (1): Mori Anna
- Former Kenkyuuseis (5): Ito Ayaka, Ishiguro Atsuki, Kinumoto Momoko, Takamatsu Eri, Fujimoto Sara
10th Generation
- Announced March 2010
Members (10): Abe Maria · Izuta Rina · Ichikawa Miori · Iriyama Anna · Iwasaki Hitomi · Kato Rena · Kanazawa Yuuki · Kobayashi Marina · Nakamata Shiori · Fujita Nana
- Now on Team A (1): Iriyama Anna
- Now on Team K (2): Abe Maria, Fujita Nana
- Now on Team B (1): Kato Rena
- Now on Team 4 (1): Izuta Rina
- Now on NMB48 Team BII (1): Ichikawa Miori
- Announced Graduation (1): Kobayashi Marina
- Now Graduated (1): Nakamata Shiori
- Former Kenkyuuseis (2): Iwasaki Hitomi, Kanazawa Yuuki
11th Generation
- Announced July 2010
Members (10): Ushikubo Sara · Okazaki Chinami · Kawaei Rina · Kawakami Marina · Kojima Natsuki · Suzuki Shihori · Toyoda Saki · Natori Wakana · Morikawa Ayaka · Yamaguchi Nau
- Now on Team A (1): Kojima Natsuki
- Now on Team 4 (1): Natori Wakana
- Announced Graduation (1): Kawaei Rina
- Now Graduated (2): Morikawa Ayaka, Suzuki Shihori
- Former Kenkyuuseis (5): Ushikubo Sara, Okazaki Chinami, Toyoda Saki, Kawakami Marina, Yamaguchi Nau
12th Generation
- Announced April 2011
Members (10): Tano Yuka · Suzuki Rika · Saeed Yokota Erena · Takahashi Juri · Hirata Rina · Omori Miyu · Muto Tomu · Iwata Karen · Sasaki Yukari | Eguchi Aimi (joined the group on 2011/06/11)
- Now on Team A (3): Iwata Karen, Sasaki Yukari, Hirata Rina
- Now on Team K (2): Tano Yuka, Muto Tomu
- Now on Team 4 (2): Omori Miyu, Takahashi Juri
- Former Kenkyuuseis (3): Suzuki Rika, Saeed Yokota Erena, Eguchi Aimi
13th Generation
- Announced September 2011
Members (16): Aigasa Moe · Amemiya Maika · Iwatate Saho · Umeta Ayano · Oshima Ryoka · Okada Ayaka · Kita Shiori · Kitazawa Saki · Shinozaki Ayana · Takashima Yurina · Hasegawa Haruna · Mitsumune Kaoru · Murayama Yuiri · Mogi Shinobu · Moriyama Sakura · Watanabe Nene
- Now on Team K (3): Aigasa Moe, Shinozaki Ayana, Mogi Shinobu
- Now on Team B (2): Oshima Ryoka, Umeta Ayano
- Now on Team 4 (4): Iwatate Saho, Okada Ayaka, Kitazawa Saki, Murayama Yuiri
- Now graduated (2): Mitsumune Kaoru, Takashima Yurina
- Former kenkyuuseis (5): Amemiya Maika, Kita Shiori, Hasegawa Haruna, Moriyama Sakura, Watanabe Nene
14th Generation
- Announced July 2012
Members (6): Hashimoto Hikari · Kojima Mako · Maeda Mitsuki · Nishino Miki · Okada Nana · Uchiyama Natsuki
- Now on Team B (1): Uchiyama Natsuki
- Now on Team 4 (3): Okada Nana, Kojima Mako, Nishino Miki
- Now graduated (1): Hashimoto Hikari, Maeda Mitsuki
15th Generation
- Announced May 2013
Members (12): Ichikawa Manami · Owada Nana · Komiyama Haruka · Sato Kiara · Tsuchiyasu Mizuki · Fukuoka Seina · Mukaichi Mion · Yumoto Ami | Okawa Rio · Tatsuya Makiho (added October 28, 2013) | Ino Miyabi· Taniguchi Megu (added April 14, 2014)
- Now on Team A (2): Owada Nana, Taniguchi Megu
- Now on Team K (3): Ichikawa Manami, Mukaichi Mion, Yumoto Ami
- Now on Team B (2): Tatsuya Makiho, Fukuoka Seina
- Now on Team 4 (4): Ino Miyabi, Okawa Rio, Komiyama Haruka, Sato Kiara
- Now Graduated (1): Tsuchiyasu Mizuki
Transferred Members
1st Generation
- Announced February 2014
Members (4): Ogasawara Mayu, Kizaki Yuria, Nakanishi Chiyori, Nozawa Rena
- Now in Team A (2): Ogasawara Mayu, Nakanishi Chiyori
- Now in Team B (1): Kizaki Yuria
- Now in Team 4 (1): Nozawa Rena
Concurrent Members
1st Generation
- Announced March 2012
Members (2): Matsui Jurina, Watanabe Miyuki
- Now in Team K (1): Matsui Jurina
- Concurrency Ended (1): Watanabe Miyuki
- Watanabe Miyuki returned as a Kennin member for the 6th Generation
2nd Generation
- Announced August 2012
Members (2): Ishida Anna, Kotani Riho
- Concurrency Ended (2): Ishida Anna, Kotani Riho
- Kotani Riho returned as a concurrent member for the 5th Generation
3rd Generation
- Announced April 2013
Members (6): Kodama Haruka, Yagura Fuuko, Furuhata Nao, Miyazawa Sae, Takajo Aki, Suzuki Mariya
- Now in Team K (2): Kodama Haruka, Suzuki Mariya
- Concurrency Ended (4): Miyazawa Sae, Takajo Aki (Transferred permanently to Team B), Yagura Fuuko, Furuhata Nao
- Miyazawa Sae has held a concurrent position with Team S since February 24, 2014
4th Generation
- Announced June 2013
- Concurrency Ended (1): Nozawa Rena (Transferred permanently to Team B)
5th Generation
- Announced February 2014
Members (6): Ikoma Rina, Kotani Riho, Shibuya Nagisa, Tomonaga Mio, Miyawaki Sakura, Yamamoto Sayaka
- Now in Team A (1): Miyawaki Sakura
- Now in Team K (1): Yamamoto Sayaka
- Now in Team 4 (2): Tomonaga Mio, Shibuya Nagisa
- Concurrency Ended (2): Ikoma Rina, Kotani Riho
6th Generation
- Announced March 2015
Members (6): Shiroma Miru, Sakaguchi Nagisa, Kitagawa Ryoha, Nakano Ikumi, Yabuki Nako, Yamada Nanami, Watanabe Miyuki
- Now in Team A (2): Shiroma Miru, Yamada Nanami
- Now in Team K (1): Nakano Ikumi
- Now in Team B (3): Sakaguchi Nagisa, Yabuki Nako, Watanabe Miyuki
- Now in Team 4 (1): Kitagawa Ryoha
Draft Members
1st Generation
- Announced November 2013
Members (6): Nishiyama Rena · Takita Kayoko · Gotou Moe · Shimoguchi Hinana · Yokoshima Aeri · Kawamoto Saya
- Now in Team A (2): Takita Kayoko, Nishiyama Rena
- Now in Team K (1): Shimoguchi Hinana
- Now in Team B (2): Gotou Moe, Yokoshima Aeri
- Now in Team 4 (1): Kawamoto Saya
2nd Generation
- Announced May, 2015
Members (7): Hiwatashi Yui, Nomura Nao, Kubo Satone, Takahashi Kira, Nishikawa Rei, Yamabe Ayu, Chiba Eri
- Still part of Team Kenkyuusei (7); Hiwatashi Yui, Nomura Nao, Kubo Satone, Takahashi Kira, Nishikawa Rei, Yamabe Ayu, Chiba Eri
Team 8 Toyota Members
- Announced April 2014
Members (49): Abe Mei, Iwasaki Moeka, Okabe Rin, Oguri Yui, Ota Nao, Oda Erina, Onishi Momoka, Kita Reina, Gyouten Yurina, Kuranoo Narumi, Kondo Moeri, Sakaguchi Nagisa, Sato Akari, Sato Shiori, Sato Nanami, Shitao Miu, Shimizu Maria, Shimoaoki Karin, Takaoka Kaoru, Takahashi Ayane, Tani Yuri, Tanikawa Hijiri, Chou Kurena, Nakano Ikumi, Nagano Serika, Hashimoto Haruna, Hama Sayuna, Hamamatsu Riona, Hayasaka Tsumugi, Hitomi Kotone, Hidaritomo Ayaka, Hirose Natsuki, Fukuchi Rena, Fujimura Natsuki, Honda Hitomi, Miyazato Rira, Mogi Kasumi, Moriwaki Yui, Yaguchi Moka, Yamada Nanami, Yamamoto Ai, Yamamoto Ruka, Yokomichi Yuri, Yokoyama Yui, Yoshikawa Nanase, Yoshino Miyu | Hattori Yuna (added July 27, 2014) | Yoshida Karen (added April 3, 2015)
- Now on Team 8 (47): Abe Mei, Iwasaki Moeka, Okabe Rin, Hattori Yuna, Oguri Yui, Ota Nao, Oda Erina, Onishi Momoka, Kita Reina, Gyouten Yurina, Kuranoo Narumi, Kondo Moeri, Sakaguchi Nagisa, Sato Akari, Sato Shiori, Sato Nanami, Shitao Miu, Shimizu Maria, Shimoaoki Karin, Takaoka Kaoru, Takahashi Ayane, Tani Yuri, Tanikawa Hijiri, Chou Kurena, Nakano Ikumi, Nagano Serika, Hashimoto Haruna, Hama Sayuna, Hamamatsu Riona, Hayasaka Tsumugi, Hitomi Kotone, Hidaritomo Ayaka, Hirose Natsuki, Fukuchi Rena, Fujimura Natsuki, Honda Hitomi, Miyazato Rira, Mogi Kasumi, Yaguchi Moka, Yamada Nanami, Yamamoto Ai, Yamamoto Ruka, Yokomichi Yuri, Yokoyama Yui, Yoshikawa Nanase, Yoshino Miyu, Yoshida Karen
- Now Graduated (2): Okubora Chinatsu, Moriwaki Yui
Temporary Members
Otona AKB48
- Duration: April - September 2014
Members (1): Tsukamoto Mariko
Baito AKB
- Baito AKB
- Baito AKB Paruru Selection