In a futuristic era, The World is a peace-bringing entity. Though no one knows its location, it has watched over Earth for so long that war has become merely a fable. The airship Norn's task is to deliver nine ability users to The World. After collecting the last person, Norn takes off. Included onboard are eight men and three women—Koharu, who has finally escaped her loneliness and detests her destructive power; Mikoto Kuga, born to a noble family, who uses her barrier skill to protect the Norn and those it carries; and Nanami Shiranui, whose ability only brings pain, and who wishes to die for a past sin she has committed. While en route, suspicions arise amongst the passengers when they realize there are too many people onboard. As they try to determine who has snuck aboard, the ship is attacked by an unknown assailant aiming to stop the Norn's progress at all costs. From this chaos arises questions: why were they granted powers, and what must they do once they reach The World?

Hana Ichinose, a 17-year-old high school student who is not only introverted, but also insecure and timid, has just moved and will be attending a new school. To make her situation more difficult, Hana is a slow start, which means that she missed a year and worries about attending a class where everyone is younger than her. During her introduction, the teacher reveals it is Hana's birthday, which gives her the jumping-off point to meet three of her classmates: Tamate Momochi, a charismatic and extroverted girl; Kanmuri Sengoku, who is shy and small; and the popular and pretty Eiko Tokura. Not wanting to lose the chance to make new friends, Hana's interactions with these three mark the beginning of some beautiful relationships that will change her life.

Koyomi Araragi spent his last year of high school helping girls in his town resolve various supernatural afflictions. But now Araragi has departed for university, leaving his friends to fend for themselves against new problems and curses that plague them. Yotsugi Ononoki, once a human corpse and now a living doll, takes residence in Araragi's home, keeping watch over his sister Tsukihi, a girl harboring a mystical secret of her own. As part of her duties, Yotsugi fills Araragi's vacated role as occult expert, assisting others in town with their issues. One of these girls, middle school student Nadeko Sengoku, slowly recovers from her own recent brushes with the paranormal. She avoids returning to school, instead spending time alone in her room and pursuing her dream of becoming a professional manga artist. In order to speed up Nadeko's quest for mastery of her craft, Yotsugi convinces her to create four copies of herself, each representing a distinct aspect of Nadeko's personality. However, the clones refuse to help Nadeko, instead escaping into the town and creating a chaotic mess. Now forced to grapple with her own fractured sense of identity, Nadeko sets out to capture them and resolve her inner conflict.

The Japanese call them hikikomori—people who've become so withdrawn socially that they refuse to leave their homes for weeks and even months at a time. For Sasami Tsukuyomi, who's attempting to pass her first year of high school despite being a shut in, it's more than just a word. Fortunately though, she lives with her older brother Kamiomi, who just happens to be a teacher at the school Sasami is supposed to attend. Not to mention, her Brother Surveillance Tool which lets her view the outside world via her computer and will, theoretically, allow her to readjust to interfacing with people again. What it mainly does, however, is let her view her brother's interactions with the three very odd Yagami sisters, who inexplicably seem to have had their ages reversed and have various types of interest in Kamiomi. And then things start to get really weird... Magical powers? Everything turning into chocolate? Is life via the web warping Sasami's brain, or is it the universe that's going crazy? (Source: Sentai Filmworks)