Idol Nicknames

[Okayu]

This topic is for collecting a list of idol nicknames, either used in the series or by fans. If it's used by a certain character in series be sure to include the name.
Add any you'd like and they'll be edited onto the list. For starters it'll be simple but more will be added with time.

765 Production
Haruka Amami - Harurun, Harukakka
Chihaya Kisaragi - Chi-chan, Chihya
Yukiho Hagiwara - Yukipo, Yukipyon
Yayoi Takatsuki - Yayoicchi
Makoto Kikuchi - Makochin, MakoMakoRin~
Mami Futami
Iori Minase - Iorin
Ami Futami
Azusa Miura
Ritsuko Akizuki - Ricchan
Miki Hoshii - Miki Miki
Takane Shijou - Ohime-chin
Hibiki Ganaha - Hibikin, Bikki (by Julia)

Kotori Otonashi - Piyopiyo
Junjirou Takagi
(2011 anime) Producer - AkabaneP (after his voice actor Kenji Akabane), Broducer

[Former]
Junichirou Takagi

961 Production
Leon

Takao Kuroi

[Former]
Miki Hoshii - Miki Miki
Takane Shijou - Ohime-chin
Hibiki Ganaha - Hibikin

Touma Amagase - Amatou (by Futami twins), Onigashima
Hokuto Ijuuin - Hoku Hoku (by Futami twins)
Shouta Mitarai

876 Production (Dearly Stars)
Ai Hidaka
Eri Mizutani
Ryo Akizuki

Minori Ishikawa
Manami Okamoto
Reiko Ozaki
Souichi Takeda

346 Production (Cinderella Girls)
Uzuki Shimamura - Shimamu (by Mio), Shimamura-san, Uzupaka
Rin Shibuya - Shiburin (by Mio)
Mio Honda - Chanmio
Anastasia - Anya
Minami Nitta - Minamin, "walking sex/歩くセックス"
Ranko Kanzaki - Ran Ran (by Mio)
Anzu Futaba - Anzuchang
Chieri Ogata
Kanako Mimura
Kirari Moroboshi
Rika Jougasaki
Miria Akagi
Riina Tada - Dariina (by Natsuki), Niiwaka/Niiwakawaii (Poser/Posercute)
Miku Maekawa - Miku-nyan (by Mio)

Mika Jougasaki
Mizuki Kawashima
Mayu Sakuma
Akane Hino
Miho Kohinata

Sachiko Koshimizu
Nana Abe - Usamin
Sae Kobayakawa - Sae-han (dialect)
Koume Shirasaka
Kaede Takagaki
Airi Totoki
Aiko Takamori - Barrel (3 sizes)
Yuko Hori
Syoko Hoshi
Natsuki Kimura

(CG anime) Producer - TakeuchiP (after his voice actor Shunsuke Takeuchi)
Chihiro Senkawa

765THEATER ALLSTARS (Million Live)
Mirai Kasuga - Mirai-cha
Hinata Kinoshita
Julia
Sayoko Takayama
Kotoha Tanaka
Tomoka Tenkubashi
Serika Hakozaki
Arisa Matsuda
Shizuka Mogami - Shizu (by Julia)
Anna Mochizuki
Kana Yabuki

Emily Stewart
Tamaki Ogami
Reika Kitakami
Umi Kousaka - Umimi
Minako Satake - Minarin (by Mami)
Elena Shimabara
Subaru Nagayoshi
Akane Nonohara
Konomi Baba
Noriko Fukuda
Ayumu Maihama
Mizuki Makabe
Rio Momose
Nao Yokoyama

Tsubasa Ibuki
Shiho Kitazawa
Karen Shinomiya
Yuriko Nanao - Yuyurin (by Umi)
Momoko Suou
Matsuri Tokugawa
Megumi Tokoro
Fuka Toyokawa
Iku Nakatani
Chizuru Nikaido
Roco Handa
Miya Miyao

315 Production (SideM)
Touma Amagase - Amatou (by Futami twins), Onigashima
Teru Tendo
Minori Watanabe
Shiki Iseya
Hayato Akiyama

Hokuto Ijuuin - Hoku Hoku (by Futami twins)
Kaoru Sakuraba
Kyoji Takajo
Jun Fuyumi
Natsuki Sakaki
Kyosuke Aoi
Michio Hazama
Jiro Yamashita

Shouta Mitarai
Tsubasa Kashiwagi
Pierre
Haruna Wakazato
Yusuke Aoi
Rui Maita
Ryo Akizuki

Other Characters

[MetalPredat0r]

Here's some nicknames courtesy of the Futami Twins, Mio, Umi, and Julia.

Uzuki: Shimamu
Rin: Shiburin
Ranko: Ran Ran
Minami: Minamin
Miku: Miku-nyan

Yuriko: Yuyurin
Shizuka: Shizu
Minako: Minarin

Touma: Amatou
Hokuto: Hoku Hoku

[Maka]

Oh man, here's all the ones I can remember...

Anzu was called Anzuchang a couple of years ago on /a/ for some reason. It's old, like 2012 old, though.

Touma has Onigashima, which is... Visually close to his surname, I guess? It's from a commu in imas 2.

Umi gets called Umimi due to the kanji in her name.

Anastasia gets called Anya both in CG itself and by fans.

Riina has Dariina by Natsuki, and Niiwaka/Niiwakawaii (Poser/Posercute) by fans.

Uzuki used to get called Shimamura-san but I think Shimamu has overtaken that...

Aiko = barrel, because of her figure.

I vaguely remember Sae being called Sae-han because of her dialect.

Not a nickname, but Minami gets related to the phrase "walking sex/歩くセックス" a lot because of her girl next door charm. Sometimes it's turned into "walking secrosse".

[Cael K.]

Chanmio! (ちゃんみお) - Mio Honda. It's a fan nickname that... I think is still used occasionally.

Bosamura-san (ぼさ村さん)  - Uzuki with bed hair. Portmanteau of bosabosa (ぼさぼさ, ruffled hair), and Shimamura.
Archangel Uzukeil (大天使ウヅキエル) - I've only seen this around once or twice, but it's Shimamura Uzuki at her most saintly.

[zaitcev]

Uzuki: Shimamu

Uzuki gets called Uzupaka in the in-game comic, so this is fully canon even if not occurring in the anime so far. It even happens twice.

[Tengu B]

Chanmio is used quite often, it was in the Twitter trends after last week's episode after all.

Speaking of Mio, Mio has a huge list of nicknames she calls all the other idols, many of which she came up with during her segment on the radio Cinderella Party.
http://dic.pixiv.net/a/%E6%9C%AC%E7%94%B0%E6%9C%AA%E5%A4%AE#h2_9

I might go through this, it'll take some time.
Shiburin had been a common nickname before Mio used it though.

A-chan/Ah-chan （あーちゃん） for Aiko is from Mio.

Kirarin （きらりん） for Kirari in general.

And I was reminded from Uzukiel, but
Chieriel （チエリエル） and Archangel Chieriel　（大天使チエリエル） are used a bit as well.

Miku-nyan or Mikunyan （みくにゃん） for Maekawa Miku

Aiko's joke nickname is Drum Can (ドラム缶）in Japanese (as opposed to barrel).
And if joke nicknames are allowed, might as well add 72 and Manaita まな板(Cutting Board) for Chihaya.

[ChocoCats]

Tenteru (てんてる) for Teru.

Kaoru Sensei or Sensei for Kaoru Sakuraba. There's also Dr. Kisaragi but I need to confirm that.

Shiki calls his friends (Jun, Haruna, Natsuki, and Hayato) by their given name in katakana plus "cchi" in the end.

[Amazing_Grace]

Do the twins' "Azusa-oneechan" and "Chihaya-oneechan" count?

On that vein, do nicknames from Xenoglossia count? Because if so, Haruka has Baka Ribbon.

Also, Deko-chan for Iori. Courtesy of Miki.

Booberella for Azusa courtesy of me