Penguin Musume♥Heart

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.
(Source: ANN)

A strong fighter from China. She made a promise with Kujira at a younger age, (who was still under the delusion she was a boy) that if Chi-Cha could defeat her, Kujira would become her husband. While Kujira has since realized she was a girl and has made it very clear to all, Chi-Cha still remains clueless and vows to make her her husband someday.

Cha Chi

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.  (Source: Wikipedia)

Kujira Etorofu

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.

Nene Kurio

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".

Sakura Nankyoku

Penguin's rival, represented by a polar bear. 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.  (Wiki)

Mary Chupacabra W. Whitebear

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.  (Source: Wikipedia)

Saki Hojiro

Maguro Hojiro is Marie'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.

Maguro Houjiro

One of Mary's four knights. Actually a man who really enjoys wearing dresses.

Kare Ijuin

Penguin, Invade!

A girl who introduces herself to people as "Penguin" and who loves animation, has transferred to Hokkyoku High School. Her real name is Sakura Nankyoku.

Sha's Counterattack!

While Sakura is pressing Kujira to wear a costume from her favorite animation "Takenoko-chan," a pretty intruder appears.

My Sister Is a Third Grader

While Sakura is attending the regular meeting of the Hokkyoku Student Council, Kaede, her younger sister, comes to bring a forgotten item.

Walking Under the Night Sky

Kaede arrives at the Hokkyoku-cho Fireworks Show, in the company of the regular members, all dressed in yukata.

Mary-sama Watches Over Us

A mysterious beauty by the name of Mary Chupacabra W. Whitebear sends a challenge to Sakura Nankyoku!

Chi Is My Master

Sha Chi tries to attack Sakura, who as always clings to her favorite friend, Kujira.

The All-loving Shrine Maiden

Nene performs one miracle after another in front of Sakura and Kujira.... It turns out that Nene Kurio is a shrine maiden.

The Targeted School

The sinister reach of Whitebear Corporation led by Mary Chupacabra W. Whitebear extends to Sakura.  A well-prepared and heinous trick threatens the closure of Hokkyoku High School.