2015 Happenings

people
- 2 0 ex-leaders
- 23 -26 joined groups
- 9 -4 left groups
- 1 0 new leaders
- 1 1 disbanded groups
- 2 -3 new groups
- 9 -8 new idols
- 2 -3 graduations
- 2 -2 retirements
- 0 0 born
music
- 5 -6 new albums
- 15 -12 new singles

October 2015
- 14
  - Kikkawa You releases “TBD”
September 2015
- 6
  - Tsubaki Factory releases “Seishun Manmannaka”
- 2
  - Kobushi Factory releases “Dosukoi! Kenkyo ni Daitan / Ramen Daisuki Koizumi-san no Uta / Nen ni wa Nen (Nen Iri Ver.)”
August 2015
- 19
  - Morning Musume｡’15 releases “Oh my wish! / Sukatto My Heart / Ima Sugu Tobikomu Yuuki”
- 8
  - Yamagishi Riko becomes leader of Tsubaki Factory
- 5
  - Country Girls releases “Wakatteiru no ni Gomen ne / Tamerai Summertime”
July 2015
- 22
  - ANGERME releases “Nana Korobi Yaoki / Gashin Shoutan / Mahou Tsukai Sally”
- 15
  - Juice=Juice releases “First Squeeze!”
- 8
  - Ciao Bella Cinquetti releases “Omotesando / Futako Tamagawa / Never Never Give Up”
- 1
  - LoVendoЯ releases “Iin Ja nai? / Futsuu no Watashi Ganbare!”
June 2015
- 12
  - Shimamura Uta leaves Hello! Project
    
    H!P
  - Shimamura Uta retires from show business
  - Shimamura Uta leaves Country Girls
May 2015
- 8
  - Kikkawa You releases “Hana”
April 2015
- 29
  - Tsubaki Factory is formed
    with Ogata Risa, Yamagishi Riko, Niinuma Kisora, Tanimoto Ami, Kishimoto Yumeno and Asakura Kiki
- 27
  - Ono Mizuho joins Hello! Project
    
    H!P
  - Nakano Rion joins Hello! Project
    
    H!P
  - Yanagawa Nanami joins Hello! Project
    
    H!P
  - Maeda Kokoro joins Hello! Project
    
    H!P
  - Akiyama Mao joins Hello! Project
    
    H!P
  - Kanatsu Mizuki joins Hello! Project
    
    H!P
  - Kasahara Momona joins Hello! Project
    
    H!P
  - Okamoto Honoka joins Hello! Project
    
    H!P
  - Ono Mizuho joins HelloPro Kenshuusei
  - Nakano Rion joins HelloPro Kenshuusei
  - Yanagawa Nanami joins HelloPro Kenshuusei
  - Maeda Kokoro joins HelloPro Kenshuusei
  - Akiyama Mao joins HelloPro Kenshuusei
  - Kanatsu Mizuki joins HelloPro Kenshuusei
  - Kasahara Momona joins HelloPro Kenshuusei
  - Okamoto Honoka joins HelloPro Kenshuusei
- 15
  - Morning Musume｡’15 releases “Seishun Kozou ga Naiteiru / Yuugure wa Ameagari / Ima Koko Kara”
- 8
  - Juice=Juice releases “Wonderful World / Ça va? Ça va?”
- 1
  - ℃-ute releases “The Middle Management ~Josei Chuukan Kanrishoku~ / GamushaLIFE / Tsugi no Kado wo Magare”
March 2015
- 26
  - Kobushi Factory releases “Nen ni wa Nen / Survivor”
- 25
  - Country Girls releases “Itooshikutte Gomen ne / Koi Dorobou”
- 17
  - Up Up Girls (Kari) releases “Third Album (Kari)”
- 8
  - Hirose Ayaka becomes leader of Kobushi Factory
- 3
  - Berryz Koubou disbands
    with Shimizu Saki, Tsugunaga Momoko, Tokunaga Chinami, Sudou Maasa, Natsuyaki Miyabi, Kumai Yurina and Sugaya Risako
  - Shimizu Saki leaves Berryz Koubou
  - Shimizu Saki steps down as leader of Berryz Koubou
  - Tsugunaga Momoko leaves Berryz Koubou
  - Tokunaga Chinami leaves Berryz Koubou
  - Sudou Maasa leaves Berryz Koubou
  - Natsuyaki Miyabi leaves Berryz Koubou
  - Kumai Yurina leaves Berryz Koubou
  - Sugaya Risako leaves Berryz Koubou
- 1
  - Takase Kurumi joins Hello! Project
    
    H!P
  - Takase Kurumi joins HelloPro Kenshuusei
February 2015
- 25
  - Mikame Kana leaves Hello! Project
    
    H!P
  - Mikame Kana retires from show business
  - Mikame Kana leaves HelloPro Kenshuusei
- 18
  - HelloPro Kenshuusei releases “① Let's say "Hello!"”
- 4
  - ANGERME releases “Taiki Bansei / Otome no Gyakushuu”
January 2015
- 21
  - Berryz Koubou releases “Kanjuku Berryz Koubou The Final Completion Box”
- 14
  - Maeda Irori releases “Twinkle Star Light / Himitsu”
- 2
  - Kobushi Factory is formed
    with Fujii Rio, Hirose Ayaka, Nomura Minami, Ogawa Rena, Hamaura Ayano, Taguchi Natsumi, Wada Sakurako and Inoue Rei