The Takakura family (brothers Kanba, Shoma and their sister Himari) have breakfast with each other and treat their sister to a day at the aquarium in Ikebukuro. Unfortunately, after buying a hat for her, their sister collapses outside. She gets rushed to the hospital, but the doctors are unable to save her and declare her dead.
Just as the brothers are grieving, Himari abruptly sits up in bed as another voice claims to have extended her lease on life in exchange for some sort of price, but she doesn't say what the price is as the penguin hat falls off her head. The brothers don't really care, and are just happy that she is alive.
The next day, Shouma goes to school after finding that a heat-insulated package was delivered to their doorstep containing three frozen eggs. As he tries to get him, Shouma believes that a penguin only he can see is stalking him. When he reaches home, it turns out that his siblings already figured out the penguins, that only they can see them, yet they can understand Japanese speech and help out around the house.
Suddenly, the other voice inside Himari awakens again, and transports them to some other dimension, telling them that she needs them to find the Penguin Drum, and has extended Himari's life in exchange for some sort of price.
|Kanba Takakura ( x ) ( x ) ( x )||
|Himari Takakura ( x ) ( x ) ( x )||
|Shouma Takakura ( x ) ( x ) ( x )||
|Yukina Kashiwagi ( x ) ( x ) ( x )||
|Ringo Oginome ( x ) ( x ) ( x )||
|Penguin #1 ( x ) ( x ) ( x )||
|Penguin #2 ( x ) ( x ) ( x )||
|Penguin #3 ( x ) ( x ) ( x )||
|Akemi Hayashi||Key Animator|
|Lily Hoshino||Original Concept||Lily Hoshino is a boys love mangaka who is well-known for her soft, pretty style.|
|Shouko Nakamura||Episode Director||Animator|
|Terumi Nishii||Character Artist/Designer||Animator.|
|Takahiro Kagami||Key Animator|
|Yoshihiko Umakoshi||Key Animator|
|Naoto Hosoda||Key Animator|
|Masahiro Aizawa||Key Animator|
|Shinya Hasegawa||Key Animator|
|Takashi Kojima||Key Animator||Penguin animator|
|Yukari Hashimoto||Music||Anime Composer|