Penguin Musume (ペンギン娘 Pengin Musume?, lit. Penguin Girl) is a Japanese manga series, written by manga author Tetsuya Takahashi. The manga was serialized in the Japanese shōnen manga magazine Weekly Shōnen Champion between 2006 and 2007. After the manga ended serialization in Weekly Shōnen Champion, the serialization was restarted from the February 2008 issue of Champion Red magazine with the Penguin Musume Max title. An original net animation adaptation entitled Penguin Musume Heart (ペンギン娘♥はぁと Pengin Musume ♥ Haato?) was streamed on Nico Nico Douga between April 19, 2008 and November 15, 2008.
The story follows Sakura 'Penguin' Nankyoku and her friends Kujira Etorofu and Nene Kurio, through their daily lives, which are often corrupted by either Penguin herself, her economic rival Mary Whitebear, or other people who have interest in the Nankyoku family.
Sakura Nankyoku is a total otaku. Due to a fluke, she gets elected as her class' Student Council President. Everything takes off from there into a series of crazy misadventures revolving around Sakura, her family, and her classmates.
- Sakura 'Penguin' Nankyoku Seiyū: Azusa Kataoka
The lead character who is obsessed with manga and anime. Whenever she cosplays as someone, she obtains the abilities of that outfit. She is part of a very rich family and is nicknamed Penguin due to her penguin-like hairstyle and her surname which means "South Pole". Her growing up with anime and manga has led her to have an erratic and slightly perverted personality, and she often latches onto her female friends.
- Kujira Etorofu Seiyū: Mariya Ise
A girl who is skilled in Etorofu martial arts. She was raised as a boy by her father to become a strong fighter, and whilst she has since realised she is actually a girl, her father hasn't. She is generally hounded by Penguin due to a likeness to one of her favourite anime stars.
- Nene Kurio Seiyū: Nanjou Yoshino
A calm girl who always remains composed with a smile on her face, no matter what happens. She lives near the shrine and works as a shrine maiden, but she also has some ninja-esque capabilities should the situation occur.
- Cha Chi Seiyū: Sakura Nogawa
A strong fighter from China who is skilled in her family's martial arts. She made a promise with Kujira, who was still under the delusion she was a boy, that if Cha could defeat her, Kujira would become her husband. Whilst Kujira has since realised she was a girl, Cha still remains clueless and vows to make her her husband someday, often going against people who would steal her away.
- Kaede Nankyoku Seiyū: Rina Hidaka
Penguin's younger sister, who is a lot more composed than her. She generally has to sort out Penguin's errors and punish her by sending her to 'the lecture house'.
- Mary Chupacabra W. Whitebear Seiyū: Mai Kadowaki
Penguin's rival, represented by a polar bear. She is almost always accompanied by her servants, the White Knights. A tragic moment in her past has caused her to despise the Nankyoku company, and constantly seeks to overwhelm it, normally by building something bigger than what they have. Later on though, she becomes bankrupt and has to use tattered clothing whilst maintaining her lady-like dignity. She is also referred to as 'Shirokuma' (a literal translation of Whitebear) and is sometimes called 'Kuma-san' by Penguin.
The White Knights
- Maguro Hojiro
Maguro Hojiro is Mary's right-hand woman and one of her four knights. She wears an eyepatch and a maid's outfit. Maguro has a fierce composure, but becomes shy around Kujira and communicates with cutesy text messages.
- Hunting Maria
Hunting Maria is one of Mary's four knights. She is proficient in sword techniques and has a sadistic streak, as well. It is revealed on the official website that Maria is Mary's younger sister.
- Kiyomi Kadami
Kiyomi Kadami is one of Mary's four knights. She generally shows her prowess as a quiz show host.
- Kare Ijuin
Kare Ijuin is one of Mary's four knights. Kare is actually a transvestite.
- Black Rose
Head of Kurobara Communications who organises the kidnap of Mary as bait for Penguin. She takes a rather unhealthy interest in Penguin and uses a thorned whip to punish her opponents. She is actually Penguin's mother.
Chief of Kurobara Communications. She specialises in using all kinds of cards to attack, but can also attack using her long hair. She constantly has to bail her assistant, Riff, out of jams during missions.
Aka's assistant. She is called out to execute missions for Kurobara Communications, but her actions usually end up backfiring against her.
- Sebastian Seiyū: Koji Ishii
The Nankyoku's family butler. He has a wide variety of skills used to serve Penguin and Kaede, and occasionally dresses in women's clothing.
- Saki Hojiro
Maguro's little sister. Just like her sister, she is bashful and mostly communicates through text messages. She immediately becomes the victim of Penguin's affections, but luckily seems to rather enjoy them.
- Shira K Sosu
The leader of the Hotsuyoku Yakuta, who appears in the Penguin Musume MAX manga. She constantly tries to kidnap the Nankyoku's to hold for ransom in order to pay the rent. Her name is generally forgotten by Penguin whenever they meet.
Up to the 8th episode, each episode used a slightly different opening, featuring different animations of the characters. They would generally end with a depiction of Penguin and Mary's battleships in space. The 8th episode's opening was a fan creation from a member of the site Nico Nico Douga. Since episode 9, the opening used in episode 7 has been used. The second ending animation was produced by IOSYS. The opening and ending theme song's are sung by the cast of the show.
- Opening Theme: "Renai Jiyuu Shōjo♀" (恋愛自由少女♀) by PNGN 6: Azusa Kataoka, Mariya Ise, Yoshino Nanjou, Sakura Nogawa, Mai Kadowaki, Rina Hidaka (Episodes 1-22)
- Ending Theme 1: "Yurete Hajikete Afurechau☆Miwaku no Penguin Musume" (揺れてはじけてあふれちゃう☆魅惑のペンギン娘) by PNGN 4: Azusa Kataoka, Mariya Ise, Yoshino Nanjou, Rina Hidaka (Episodes 1-11)
- Ending Theme 2: "Yurayura + Yuriyura + Nanananaa" (ゆらゆら+ゆりゆら+ななななー) by PNGN 3: Azusa Kataoka, Mariya Ise, Yoshino Nanjou (Episodes 12-22)