Example of some Kenkyuusei on AKB48's website.
AKB48 Kenkyuusei (AKB48チーム研究生) are trainee idols from AKB48 . They fill in for absent members in the theater and are promoted to official members of AKB48 to replace graduated members. They currently have 13 kenkyuuseis.
Saeki Mika - 4th Generation (美香ちぃ Mikacchi) (Team B)
Kuramochi Asuka - 4th Generation (もっちぃ Mocchii) (Team K)
Naruse Risa - 4th Generation (なるる Naruru) (Team K)
Fujie Reina - 4th Generation ( れいにゃん Reinyan) (Team A)
Sato Amina - 4th Generation (あみな Amina) (Team A)
Miyazaki Miho - 5th Generation (みゃお Myao) (Team A)
Kitahara Rie - 5th Generation (きたりえ Kitarie) (Team A)
Sashihara Rino - 5th Generation (さっしー Sasshii) (Team B)
Nito Moeno - 5th Generation (もえの Moeno ) (Team B)
Nakata Chisato - 4th Generation (ちぃちゃん Chiichan) (Team A)
Takajo Aki - 6th Generation (あきちゃ Akicha ) (Team A)
Kohara Haruka - 5th Generation (きゅるるん〜 kyururun~) (Team B)
Nakatsuka Tomomi - 5th Generation (ともちゃん Tomochan ) (Team B)
Chikano Rina - 5th Generation (チカリーナ Chikariina) (Team K)
Kikuchi Ayaka - 3rd Generation (あやりん Ayarin) (Team K)
Uchida Mayumi - 5th Generation (うっちー Ucchii ) (Team K)
Nonaka Misato - 6th Generation (みちゃ Micha) (Team K)
Matsui Sakiko - 7th Generation (さきっぺ Sakippe) (Team K)
Ishida Haruka - 5th Generation (はるきゃん Harukyan) (Team B)
Komori Mika - 7th Generation (こもりん Komorin) (Team B)
Sato Sumire - 7th Generation (すーちゃん Suuchan) (Team B)
Suzuki Mariya - 7th Generation (まりやんぬ Mariyannu) (Team A)
Oya Shizuka - 4th Generation (しーちゃん Shiichan) (Team A)
Iwasa Misaki - 7th Generation (わさみん Wasamin) (Team A)
Maeda Ami - 7th Generation (あーみん Aamin) (Team A)
Yokoyama Yui - 9th Generation (ゆい Yui) (Team K)
Suzuki Shihori - 11th Generation (しほりん Shihorin) (Team B)
Oba Mina - 9th Generation (みなるん Minarun) (Team 4)
Shimazaki Haruka - 9th Generation (ぱるる Paruru) (Team 4)
Shimada Haruka - 9th Generation (はるぅ Haruu) (Team 4)
Takeuchi Miyu - 9th Generation (みゆみゆ Miyumiyu) (Team 4)
Nagao Mariya - 9th Generation (まりやぎ Mariyagi) (Team 4)
Nakamura Mariko - 9th Generation (こまり Komari) (Team 4)
Mori Anna - 9th Generation (なんちゃん Nan-chan) (Team 4)
Yamauchi Suzuran - 9th Generation (らんらん Ran Ran) (Team 4)
Ichikawa Miori - 10th Generation (みおりん Miorin) (Team 4)
Nakamata Shiori - 10th Generation (しおりん Shiorin) (Team 4)
Abe Maria - 10th Generation (まりあ Maria) (Team 4)
Iriyama Anna - 10th Generation (あんにん Annin) (Team 4)
Kato Rena - 10th Generation (れなっち Renacchi) (Team 4)
Kawaei Rina - 11th Generation (りっちゃん Ricchan) (Team 4)
Iwata Karen - 12th Generation (カレン Karen) (Team 4)
Takahashi Juri - 12th Generation (じゅり Juri) (Team 4)
Tano Yuuka - 12th Generation (たのちゃん Tano-chan) (Team 4)
Izuta Rina - 10th Generation (いずりーな Izuriina) (Team A)
Kobayashi Marina - 10th Generation (まりんちゃん Marin-chan) (Team A)
Fujita Nana - 10th Generation (なぁな Naana) (Team K)
Kojima Natsuki - 11th Generation (なっつん Nattsun) (Team B)
Natori Wakana - 11th Generation (わかにゃん Wakanyan) (Team B)
Morikawa Ayaka - 11th Generation (あーや Aaya) (Team A)
Oshima Ryoka - 13th Generation (りょーちゃん Ryoochan) (Team A)
Muto Tomu - 12th Generation (とむ Tomu) (Team K)
Mitsumune Kaoru - 13th Generation (かおる Kaoru) (Team K)
Omori Miyuu - 12th Generation (みゆぽん Miyupon) (Team B)
Sasaki Yukari - 12th Generation (ゆかるん Yukarun) (Team A)
Hirata Rina - 12th Generation (ひらりー Hirarii/Hillary) (Team K)
Minegishi Minami - 1st Generation (みいちゃん Miichan) (Team 4)
Aigasa Moe - 13th Generation (もえちゃん Moechan) (Team 4)
Iwatate Saho - 13th Generation (さっほー Sahhoo) (Team 4)
Umeta Ayano - 13th Generation (うめたん Umetan) (Team 4)
Okada Ayaka - 13th Generation (あやか Ayaka) (Team 4)
Kitazawa Saki - 13th Generation (さっきー Sakkii) (Team 4)
Shinozaki Ayana - 13th Generation (あやなん Ayanan) (Team 4)
Takashima Yurina - 13th Generation (ゆーりん Yuurin) (Team 4)
Murayama Yuiri - 13th Generation (ゆいりー Yuirii) (Team 4)
Mogi Shinobu - 13th Generation (もぎちゃん Mogichan) (Team 4)
Hashimoto Hikari - 14th Generation (ひかり Hikari) (Team 4)
Kojima Mako - 14th Generation (こじまこ Kojimako) (Team 4)
Maeda Mitsuki - 14th Generation (みつき Mitsuki) (Team 4)
Nishino Miki - 14th Generation (みきちゃん Mikichan) (Team 4)
Okada Nana - 14th Generation (なぁちゃん Naachan) (Team 4)
Uchiyama Natsuki - 14th Generation (なっきー Nakkii) (Team 4)
Ichikawa Manami - 15th Generation (まなみ Manami) (Team A)
Owada Nana - 15th Generation (なーにゃ Naanya) (Team B)
Komiyama Haruka - 15th Generation (こみはる Komiharu) (Team 4)
Sato Kiara - 15th Generation (きぃちゃん Kiichan) (Team 4)
Tsuchiyasu Mizuki - 15th Generation (みずき Mizuki) (Team 4)
Fukuoka Seina - 15th Generation (せいちゃん Seichan) (Team B)
Mukaichi Mion - 15th Generation (みーおん Miion) (Team 4)
Yumoto Ami - 15th Generation (ゆあみ Yuami) (Team K)
Tatsuya Makiho - 15th Generation (まき Maki) (Team A)
Okawa Rio - 15th Generation (りお Rio) (Team 4)
Iino Miyabi - 15th Generation (みやび Miyabi) (Team A)
Taniguchi Megu - 15th Generation (めぐたん Megutan) (Team A)
Hiwatashi Yui - 2nd Generation Draftee (ゆいちゃん Yuichan) (Team A)
Ma Chia-Ling - AKB48 Taiwan Audition member (Team B)
Kubo Satone - 2nd Generation Draftee (さとぴー Satopii) (Team K)
Nishikawa Rei - 2nd Generation Draftee (れい Rei) (Team B)
Yamabe Ayu - 2nd Generation Draftee (あゆ Ayu) (Team B)
Chiba Erii - 2nd Generation Draftee (えりい Erii) (Team 4)
Suzuki Kurumi (くるるん Kururun) - 16th Generation (Team A)
Taguchi Manaka (まなか Manaka) - 16th Generation (Team A)
Maeda Ayaka (あやか Ayaka) - 16th Generation (Team A)
Muto Orin (おりん Orin) - 16th Generation (Team K)
Yasuda Kana (かなぶん Kanabun) - 16th Generation (Team K)
Asai Nanami (なーみん Naamin) - 16th Generation (Team 4)
Inagaki Kaori (かおり Kaori) - 16th Generation (Team 4)
Taya Misaki (たっちゃん Tacchan) - 16th Generation (Team 4)
Yamauchi Mizuki (ずっきー Zukkii) - 16th Generation (Team 4)
Nagatomo Ayami (あやみん Ayamin) - 16th Generation (Team K)
Yamane Suzuha (ずんちゃん Zunchan) - 16th Generation (Team A)
Omori Maho (まほぴょん Mahopyon) - 3rd Generation Draftee (Team B)
Tada Kyoka (きょうか Kyouka, きょん Kyon, 多田先輩 Tada-sensei) - 3rd Generation Draftee (Team 4)
Yahagi Moeka (もえちゃん Moe-chan, ふくちゃん Fuku-chan, もんた Monta, もえか Moeka, はぎもえ Hagimoe, もえにゃ Moenya) - 3rd Generation Draftee (Team K)
Kurosu Haruka (はーちゃん Haachan) - 16th Generation (Team 4)
Okada Rina (おかりな Okarina) - 3rd Generation Draftee (Team K)
Kobayashi Ran (らんちゃん Ran-chan, らんたん Rantan) - 3rd Generation Draftee (Team K)
Otake Hitomi (とっぱちゃん Toppa-chan, おおたけ Otake) - 3rd Generation Draftee (Team B)
Saito Haruna (はーたん Haatan) - 3rd Generation Draftee (Team B)
Sato Minami (さとみな Satomina) - 16th Generation (Team A)
Michieda Saki (さきぽん Sakipon) - 16th Generation (Team A)
Honda Sora (そらちゃん Sorachan) - 3rd Generation Draftee (Team A)
Furukawa Nazuna (なづなん Nazunan, 古川 Furukawa) - 3rd Generation Draftee (Team A)
Nagano Megumi (めぐみん Megumin) - 3rd Generation Draftee (Team K)
Ishiwata Sena (せなたん Senatan) - 3rd Generation Draftee (Team 4)
Homma Mai (まいちゃん Maichan) – 16th Generation (Team 4)
Kuramoto Miyuu (くらら Kurara, みゆう Miyuu) - 3rd Generation Draftee (Team 4)
Yoshihashi Yuzuka (ゆず Yuzu) - 3rd Generation Draftee (Team 4)
Ota Yuki (ゆきたん Yukitan) (17th Generation)
Kohama Kokone (こっこ Kokko) (17th Generation)
Sato Airi (あいちゃん Aichan) (17th Generation)
Hashimoto Eriko (えりちゃん Erichan) (17th Generation)
Hatakeyama Nozomi (のんちゃん Nonchan) (17th Generation)
Hirata Yuki (ゆき Yuki) (17th Generation)
Hotei Moka (ほてちゃん Hotechan) (17th Generation)
Masai Mayuu (まゆうちゃん Mayuchan) (17th Generation)
Mizushima Miyuu (みずみん Mizumin) (17th Generation)
Yamazaki Sora (そらら Sorara) (17th Generation)
Nakanishi Yuka - 4th Generation (August, 2008) (SKE48 )
Iso Reina - Team B Candidate (December, 2006)
Otsuka Aki - Team B Candidate (December, 2006)
Sakata Ryo - Team B Candidate (December, 2006)
Fujishima Mariachika - Team B Candidate (December, 2006)
Deguchi Aki - 4th Generation (November, 2007)
Iinuma Yurina - 4th Generation (November, 2007)
Kaneko Satomi - 4th Generation (November, 2007)
Kozuka Rina - 4th Generation (November, 2007)
Yoshioka Saki - 4th Generation (November 2007)
Watanabe Marie - 4th Generation (November, 2007)
Nishizawa Sara - 6th Generation (August, 2008)
Katano Yurie - 6th Generation (September, 2008)
Suzuki Nae - 4th Generation (January, 2009) - 1st KKS Selection
Arima Yuka - 5th Generation (January, 2009) - 1st KKS Selection
Hatayama Arisa - 5th Generation (January, 2009) - 1st KKS Selection
Tomita Mayu - 5th Generation (January, 2009) - 1st KKS Selection
Suzuki Shihori - 7th Generation (August, 2009)
Ishiguro Remi - 7th Generation (January, 2009)
Saotome Miki - 3rd Generation (Previously a Team B member. April, 2009)
Uriya Akane - 4th Generation (April, 2009)
Katono Mizuho - 7th Generation (June, 2009)
Komatsu Mizuki - 8th Generation (July, 2009)
Hayashi Ayano - 7th Generation (July, 2009)
Nishikawa Nanami - 8th Generation (July, 2009)
Sugiyama Miku - 8th Generation (December, 2009) - 3rd KKS Selection
Asai Madoka - 8th Generation (December, 2009) - 3rd KKS Selection
Ishii Ayaka - 8th Generation (December, 2009) - 3rd KKS Selection
Ishibe Aya - 8th Generation (December, 2009) - 3rd KKS Selection
Kaku Grace - 8th Generation (December, 2009) - 3rd KKS Selection
Komizu Nanami - 8th Generation (December, 2009) - 3rd KKS Selection
Sakamoto Rio - 8th Generation (December, 2009) - 3rd KKS Selection
Tomite Ami - 8th Generation (December, 2009) - 3rd KKS Selection
Miki Nikoru - 8th Generation (December, 2009) - 3rd KKS Selection
Muranaka Satomi - 8th Generation (Previously a 4th gen member. December, 2009) - 1st and 3rd KKS Selection
Ito Ayaka - 9th Generation (January, 2010)
Imai Yurie - 8th Generation (February, 2010)
Ishiguro Atsuki - 9th Generation (June, 2010) - 4th KKS Selection
Kinumoto Momoko - 9th Generation (June, 2010) - 4th KKS Selection
Fujimoto Sara - 9th Generation (Previously a 4th gen member. June, 2010) - 1st and 4th KKS Selection
Takamatsu Eri - 9th Generation (June, 2010)
Ueki Asaka - 8th Generation (July, 2010) - 4th KKS Selection
Sano Yuriko - 8th Generation (October, 2010) - 5th KKS Selection
Iwasaki Hitomi - 10th Generation (October, 2010) - 5th KKS Selection
Kanazawa Yuuki - 10th Generation (February, 2011)
Okazaki Chinami - 11th Generation (October, 2010)
Toyoda Saki - 11th Generation (October, 2010)
Kawakami Marina - 11th Generation (December, 2010)
Ushikubo Sara - 11th Generation (June, 2011)
Yamaguchi Nau - 11th Generation (June, 2011)
Suzuki Rika - 12th Generation (March, 2011)
Amemiya Maika - 13th Generation (August, 2012) - 6th KKS Selection
Kita Shiori - 13th Generation (August, 2012) - 6th KKS Selection
Hasegawa Haruna - 13th Generation (August, 2012) - 6th KKS Selection
Moriyama Sakura - 13th Generation (August, 2012) - 6th KKS Selection
Watanabe Nene - 13th Generation (August, 2012) - 6th KKS Selection
Saeed Yokota Erena - 12th Generation (September, 2012)
Eguchi Aimi - 12.5 Generation (May, 2013)
Noguchi Nanami - 16th Generation (March, 2017)
Takahashi Kira - 2nd Generation Draftee (Team B ) (April, 2017)
Nomura Nao - 2nd Generation Draftee (Team K ) (August, 2017)
Harasawa Otohi - 3rd Generation Draftee (Team 4 ) (August, 2018)
Kamiyama Riho - 3rd Generation Draftee (Team B ) (October, 2018)
Shoji Nagisa - 16th Generation (Team A ) (November, 2018)
Umemoto Izumi - 16th Generation (Team B ) (December, 2018)
Harima Nanami - 16th Generation (Team B ) (April, 2019)
Katsumata Saori (さおりん Saorin) - 3rd Generation Draftee (Team K ) (June, 2019)
Sato Shiori (しおり Shiori) - 3rd Generation Draftee (Team A ) (November, 2019)
Suenaga Yuzuki (ゆづちゃん Yuzu-chan) - 3rd Generation Draftee (Team K ) (November, 2020)
Hasegawa Niina (にいなん Niinan) - 17th Generation (August, 2022)
Stages
Research Students Songs on AKB48 Albums & Singles
Line-Up through the years