Yutaka Koizumi

One day, Naho Takamiya receives a letter written to herself from ten years in the future. As Naho reads on, the letter recites the exact events of the day, including the transfer of a new student into her class named Kakeru Naruse. The Naho from ten years later repeatedly states that she has many regrets, and she wants to fix these by making sure the Naho from the past can make the right decisions—especially regarding Kakeru. What's more shocking is that she discovers that ten years later, Kakeru will no longer be with them. Future Naho asks her to watch over him closely.

A terminally ill girl named Himari Takakura is miraculously saved from death by a strange spirit who resides in a penguin-shaped hat. However, in exchange for extending her life, the spirit tasks Himari's brothers, Kanba and Shōma, to seek out an elusive item known as the Penguin Drum with assistance from a trio of strange penguins.

Sato is a tangle of anxieties and conspiracy theories, believing that the nefarious N-H-K wants to turn society’s misfits into a mob of hopeless recluses. Mysterious Misaki might be able to help Sato overcome his phobias—if she can pull him out of his existential foxhole and get him to face the world.

Night Wizard. A term given to those whose mission is to protect the world from impending darkness. Renji Hiiragi is one such Night Wizard, who is constantly called on missions, even though all he wants is to be able to go to school and graduate.

Yamada is the cutest girl in the entire school, and she wants to have her way with 100 different boys before the final bell rings. There’s just one problem: she’s never even been kissed! Lucky for her, class geek Kosuda is ready to serve as her own personal Sex Ed dummy! Can these wannabe lovebirds master the art of seduction before the sun sets on high school forever?

A white ermine Okojo-san lives at an exotic pet store run by a greedy manager, until he escapes one day. In the chaos following, he ends up unconscious in a garbage can, where college student Haruka Tsuchiya finds him. Mistaking him for a ferret, Tsuchiya takes Okojo home with him. At the Shiawase apartment complex, Okojo meets other pets, including the mouse Chorori, and the various eccentric human tenants. With his friends, Okojo struggles to adapt to life with humans, vacuum cleaners, and all the other things that come with human society.

Iwaki Tomonori is a schoolboy who happens to have a crush on his teacher, but learns she has become engaged. Brokenhearted, he soon meets a girl named Rizel, a biochemically engineered human, who he learns the Japanese government has married him to against his will.

What would you do to save someone you love? All brothers Shoma and Kanba know is that, after collapsing in an aquarium and apparently dying, their terminally ill sister Himari was somehow revived by a Penguin hat that she had wished for. Now they're on an impossible mission, because the price of keeping Himari alive is to find a mysterious object called the Penguindrum, and they'll do anything to save their sister. Anything. As they travel separate paths in their search, they'll have to unravel complex riddles, make alliances with strangers they know they shouldn't trust, and question the very fabrics of time and destiny.

What would you do to save someone you love? All brothers Shoma and Kanba know is that, after collapsing in an aquarium and apparently dying, their terminally ill sister Himari was somehow revived by a Penguin hat that she had wished for. Now they're on an impossible mission, because the price of keeping Himari alive is to find a mysterious object called the Penguindrum, and they'll do anything to save their sister. Anything. As they travel separate paths in their search, they'll have to unravel complex riddles, make alliances with strangers they know they shouldn't trust, and question the very fabrics of time and destiny.