Seifuku Koujo Iinkai

 (制服向上委員会; Uniform Improvement Committee), also known as SKi, is a Japanese idol group originally formed in 1992, with slogans such as "Pure, Just and Beautiful" and "Love, Courage and Compassion".

They are currently the longest-running female idol group in Japan. To date, Seifuku Koujoi Iinkai has seen over 20 generations, 31 supporting members and 40 studio albums. They have been in a semi-inactive state since 2018, with graduated members performing under the Seifuku Koujou Iinkai name in the meantime.

Biography
Seifuku Koujou Iinkai originally debuted under Pony Canyon, but became independent in 1995, and were managed by Idol Japan Records after.

The original incarnation of the group was active until September 24th, 2006, when all members graduated and the project was rebranded as SKi Family (SKiファミリー), a collective organization of multiple groups. For a period in 2007, Seifuku Koujou Iinkai continued under the name "Hoshikawa Ririka with SKi", before ending activities entirely.

In October 2010, Seifuku Koujo Iinkai was rebooted with new members.

In the second half of 2017, Seifuku Koujou Iinkai suffered from mass-graduations. This resulted in the group having only three members, including Hashimoto Mika, who initially graduated in 2006 and had since been acting as the group's honorary chairman, and Nomiyama Anri, their 11th leader.

In October 2017, it was reported that their parent company, Idol Japan Records, would be dissolved and turned into a non-profit organization, but these plans were later put on hold. Following Nomiyama Anri's resignation in April 2018 and the withdrawal of last remaining member RAY in July, Seifuku Koujou Iinkai currently has no active members and its future is uncertain. However, reunion events with graduated members performing under the Seifuku Koujou-Tai name still take place occasionally.

Politics
Seifuku Koujou Iinkai is heavily-involved in socio-political activism, and the members volunteer in community and charity projects. Many of SKi's lyrics are critical of the Japanese government and society, and the group frequently fronts demonstrations for socio-political causes.

Seifuku Koujoi Iinkai was initially formed for two reasons; the first was to campaign for an improvement to Japanese school uniforms. The second was to combat the misogyny and exploitation faced by women in the Japanese entertainment industry, especially on television variety programmes. Since then, SKi's activism has spread to support many socio-political causes such as anti-war, anti-tobacco, preservation of the ecosystem, suicide prevention, abolition of capital punishment and the promotion of human rights.

In 1997, Seifuku Koujo Iinkai launched the "SKi Foundation" ( SKi基金), in which fans could make donations to help the group organize visits to children's homes and survivors of the Fukushima disaster. A portion of the money also goes to causes such as Amnesty International and towards the preservation of the Amazon rainforest.

Sub-Units

 * Kotobuki Tai (1995-??)
 * 4-Nin 1-Kumi (1993-2000, 2000-2006)
 * Hellow (1995-??)
 * THE DUET (2005-??)
 * Michelle (ミッシェル) (1994-1996)
 * Chihiro Shinkou Kai (千博親交会) (1996-??)
 * Shijima Koujo Iinkai (静寂向上委員会) (1996-??)
 * Yuck'er-Lee (1996-1998)
 * NAPPA (1996-??)
 * E√735 (1996-??)
 * 3M (1996-??)
 * FOUR ROSESKi (2007-??)
 * BPG (??)

First Generation

 * Yoshinari Keiko (1st leader, producer and chairman)
 * Takase Ayano (高瀬あやの) (Later changed her stage name to A-YA, and later, Hifumi Kaori)
 * Aoyama Rei (2nd leader)
 * Sato Erika (佐藤枝里子)
 * Nakano Aki (中野あき)
 * Adachi Emi (安達恵美)
 * Shimura Kazumi (志村和美)
 * Okuyama Mika
 * Aida Mashio (藍田真潮)
 * Kano Risa (加納理紗)
 * Maeda Atsuko (前田厚子)
 * Akiyama Nozomi (秋山望)
 * Takimoto Kumi
 * Shiraishi Momoko
 * Yoshida Mirai
 * Iwasaki Ai (岩崎愛)
 * Miyamoto Rieko
 * Mochizuki Nana
 * Matsuda Yukari
 * Morooka Namiko (3rd leader)
 * Nakazawa Hitomi (中沢ひとみ)

Second Generation

 * Tamura Chiaki
 * Shinohara Tomoko
 * Asano Miyuki
 * Suzuki Ryoko (鈴木涼子)
 * Mizuno Ami (水野亜美)
 * Kubo Megumi (久保愛)
 * Matsumoto Miyuki
 * Honda Hiroko (4th leader)
 * Saotome Kozue (早乙女こずえ)

Third Generation

 * Kikuchi Ayako
 * Hashimoto Mika (5th Leader, chairman)
 * Kobuyashi Hisako
 * Inoue Yukiko
 * Saito Mioko
 * Hirokawa Eiko (広川瑛子)
 * Katagiri Ryoko (片桐陵子)
 * Miyata Naomi (宮田直美)
 * Uchida Emi (内田絵美)
 * Onoda Ami (小野田亜美)
 * Matsui Yoko (松井陽子)
 * Sato Yuka (佐藤幸香)

Fourth Generation

 * Kawano Tomomi (川野朋美)
 * Ito Kayoko (伊藤嘉代子)
 * Asai Rena (麻井玲那)
 * Nakai Yuko (中井祐子)
 * Miura Eriko (三浦恵里子)
 * Yoriai Ayumi (寄合歩)

Fifth Generation

 * Akiyama Ayaka (秋山文香)
 * Hisakawa Yumiko (久川由美子)
 * Oda Saori (小田さおり)
 * Namihira Makiko (波平槙子)
 * Endo Maika (遠藤舞香)
 * Nishibori Mako (西堀真子)
 * Ishizawa Ayano (石澤彩乃)

Sixth Generation

 * Yoshida Kozue (吉田梢)
 * Koga Miyuki (古賀美雪)

Seventh Generation

 * Hoshikawa Ririka (星川りりか)
 * Morino Kana (森野加奈)
 * Takahashi Rina (高橋里奈)
 * Mizumoto Atsumi (水本あつみ)
 * Kobayashi Marina (小林万里菜)
 * Saiki Haruka (斎木春香)
 * Kawano Reina (河野伶奈)
 * Katahira Hinako (片平妃奈子)

Eighth Generation

 * Mitsuo Mafuyu (松尾真冬)
 * Matsumoto Kumiko (松本久美子)

Ninth Generation

 * Yamikoshi Chika (山越千歌)
 * Tezuka Machiko (手束真知子)

Tenth Generation

 * Nakano Azusa (中野梓)
 * Takada Yui (高田唯)
 * Kajiharu Hikaru (梶原ひかる)
 * Nakamura Saki (中村沙貴)

Eleventh Generation

 * Kato Yuna (加藤祐奈)
 * Sato Honami (佐藤帆奈美)

Twelfth Generation

 * Yano Keiko (矢野けいこ)

Thirteenth Generation

 * Ogawa Anna (小川杏奈)
 * Shimizu Karin (清水花梨)

Fourteenth Generation

 * Ikeda Rena (池田伶奈)
 * Tamano Tomoe (玉野ともえ)
 * Yoshizaki Minami (吉崎みなみ)
 * Katori Yuka (香取優花)

Fifteenth Generation

 * Kyomoto Momoka (京本百加)
 * Kida Saori (木田沙織)
 * Haruka Shione (遙詩音)

Sixteenth Generation

 * Kuno Azumi (久野あずみ)
 * Saito Miki (斎藤美輝)
 * Miyano Aichi (宮野愛沙)
 * Aizawa Misaki (相澤美沙希)
 * Fujimiya Reika (藤宮れいか)
 * Kanno Mizuki (菅野みずき)
 * Shiraishi Yuna (白石結菜)
 * Kato Mai (加藤舞)

Seventeenth Generation

 * Mori Akari (森朱里)
 * Sakuragi Maaya (桜木まあや)
 * Suzuki Ran (鈴木蘭)

Eighteenth Generation

 * Saito Noa (齋藤乃愛)
 * Saito Yuria (齋藤優里彩)

Nineteenth Generation

 * Nomiyama Anri (野見山杏里)
 * Kinashi Kana (木梨夏菜)
 * Nishino Rina (西野莉奈)
 * Tozaki Anon (斗崎歩音)
 * MIYUMI
 * Aikawa Ayaka (相澤綾香)

Twentieth Generation

 * Kaneko Yuki (金子 結稀)

Twenty-First Generation

 * RIAN
 * RAY

Twenty-Second Generation

 * Tachibana Shoko (橘しょうこ)

Support Members

 * Shimizu Erika (清水えりか)
 * Takahashi Haruka (高橋春香)
 * Sugimoto Rina (杉本梨奈)
 * Anda Mamiko (恩田麻美子)
 * Asakawa Waki (浅川和希)
 * Abe Kanako (阿部香奈子)
 * Ishizaki Mai (石崎麻里)
 * Yoshino Kiyomi (吉乃清美)
 * Sato Aki (佐藤あき)
 * Yuki Asuna (ゆうきあすな)
 * Okamoto Rina (岡本璃奈)
 * Yuki Mikiyo (結城美紀代)
 * Koike Norika (小池紀香)
 * Tsubane Agasa (局あがさ)
 * Ootake Yuka (大竹由夏)
 * Ishizduka Mizuki (石塚みづき)
 * Nakanishi Erika (中西絵里香)
 * Nakazawa Juri (中澤樹里)
 * Sakura Erika (桜えりか)
 * Akikawa Risa (秋川莉紗)
 * Segawa Hana (瀬川はな)
 * Saotome Satomi (早乙女里美)
 * Saito Tomoko (斉藤智子)
 * Nagao Chiemi (長尾智恵美)
 * Shinohara Miho (篠原美穂)
 * Aihara Misaki (愛原美咲)
 * Morimoto Haruna (森本美夏)
 * Miyata Sari (宮田沙里)
 * Hoshino Kurumi (星野くるみ)
 * Aizawa Machiru (相沢みちる)
 * NATUKI
 * kanoko
 * karen

Singles

 * [1993.03.03] Seifuku Sengen
 * [1993.05.21] Kiyokuta Dashikuutsu Kushiku
 * [1993.10.21] Egao ga Sukitsu!
 * [1995.04.17] Ohayo! / Emerald no Densetsu
 * [1995.04.17] Dokyusei
 * [1998.04.01] Hanakuso MAN ga Iku
 * [1998.11.01] Sushi-ya no Master
 * [2005.05.01] Riso to Genjitsu (PANTA & Nakagawa Goro with SKi)
 * [2006.06.20] For a Life (PANTA & Nakagawa Goro with SKi)
 * [2011.04.01] Uchimata Boogie
 * [2011.08.15] Datsu! Datsu! Datsu Genpatsu no Uta
 * [2011.10.01] Kurukuru Handkerchief
 * [2015.05.01] Aidzu Bandaisan (Seifuku Kojo Iinkai feat. Momonashi)
 * [2016.03.11] Senso to Heiwa
 * [2017.06.25] Hana ~Subete no Hito no Kokoro ni Hana wo~ (Seifuku Kojo Iinkai feat. Hashimoto Mika)

Albums

 * [1994.12.19] Ai to Yuki no Omoiyari
 * [1995.12.01] Atsui Chikyuu
 * [1996.03.01] Otona wa Wakatte Kurenai
 * [1996.07.01] Sayonara wa Deai no Ashita he no Shirushi
 * [1996.08.01] Chokan Test
 * [1996.12.01] Kizu-Darake no Seishun
 * [1997.07.01] Itsumo no Youni
 * [1997.10.01] SKi Unit-shuu Vol.2
 * [1998.01.01] Chikyuu ni Ai wo
 * [1998.05.01] Kaizoku Musume
 * [1998.08.01] ○ Denai Shoujo no x na Seikatsu
 * [1998.10.01] Kuroi Hitomi
 * [1999.01.01] Seifuku Koujo Iinkai Unit-shuu Vol.3
 * [1999.05.01] Ima Koso Tachiagare
 * [1999.11.01] Ongaku wa Keizai no Dorei Janai!
 * [2000.08.01] No! Make
 * [2001.02.01] Dai San No Me
 * [2001.04.01] SKi Unit-4
 * [2002.01.01] MY GENERATION
 * [2002.10.01] Ballerina
 * [2003.08.01] Sekai Jiyuu America
 * [2004.02.01] Kawattenai Wakattenai
 * [2005.02.01] Maa Maa
 * [2005.05.01] Nihon wo Genki ni Shita Uta
 * [2005.11.01] Duet
 * [2006.07.25] Sonohi ga Kuru Made
 * [2006.12.01] Ikiru Tame Ni
 * [2007.02.01] Oshogatsu
 * [2007.12.01] GAME
 * [2011.01.01] STOP!STOP!STOP!
 * [2011.12.01] Sekai de 1ban Shiawase
 * [2012.05.01] THE PROTESTER
 * [2013.07.01] Chikyuugi Mitsume
 * [2013.10.01] 3 Akutsuiho! (Hashimoto Mika & Seifuku Koujo Iinkai)
 * [2014.01.01] Rule to Manner wo Mamorou Yo!
 * [2016.03.11] Sensou to Heiwa
 * [2017.08.01] Omedetou (Hashimoto Mika & Seifuku Koujo Iinkai)

Best-Of Albums

 * [1996.06.01] Worst


 * [1999.02.05] BEST
 * [2003.01.01] SKi-2-the Best

Box Sets

 * [2012.12.15] Volunteer Spirit

Video Releases

 * 1) [1993.05.21] Oshare Seifuku Zukan (Natsufuku-ban) (おしゃれ制服図鑑〔夏服版〕)
 * 2) [1993.05.21] Oshare Seifuku Zukan (Fuyufuku-ban) (おしゃれ制服図鑑〔夏服版〕)
 * 3) [1993.11.26] Seifuku Koujo Iinkai Katsudo Nisshi (制服向上委員会活動日誌)
 * 4) [1994.12.19] Live Idol No.1 (ライブアイドルNo.1)
 * 5) [1995.02.22] Kettei! Original Seifuku '95 Best 20 ~Natsufuku-ban~
 * 6) [1995.02.22] Kettei! Original Seifuku '95 Best 20 ~Fuyufuku-ban~
 * 7) [1995.10.01] STUDIO LIVE '95
 * 8) [1995.11.01] Idol Japan Festival Vol.1 (アイドル・ジャパン・フェスティバル Vol.1)
 * 9) [1995.11.01] Idol Japan Festival Vol.1 (アイドル・ジャパン・フェスティバル Vol.2)
 * 10) [1995.12.01] X'MAS SONGS
 * 11) [1997.04.01] Koibito-tachi no Uta (恋人たちの歌)
 * 12) [2003.04.01] Seitan 10nensai LIVE! Part1 (生誕10年祭LIVE! Part1)
 * 13) [2003.04.01] Seitan 10nensai LIVE! Part1 (生誕10年祭LIVE! Part2)
 * 14) [2004.08.01] Idol wo Yumemita Shoujo-tachi (アイドルを夢見た少女たち)