Seikyou Private Academy, built on the intrigue of traditional occult myths, bears a dark past—for 60 years, it has been haunted by a ghost known as Yuuko, a young woman who mysteriously died in the basement of the old school building. With no memory of her life or death, Yuuko discreetly finds and heads the Paranormal Investigations Club in search of answers. A chance meeting leads Yuuko to cling to diligent freshman Teiichi Niiya, who can see the quirky ghost, they quickly grow close, and he decides to help her. Along with Kirie Kanoe, Yuuko's relative, and the oblivious second year Momoe Okonogi, they delve deep into the infamous Seven Mysteries of the storied school. Tasogare Otome x Amnesia tells a unique tale of students who work together to shed light on their school's paranormal happenings, all the while inching closer to the truth behind Yuuko's death. [Written by MAL Rewrite]

A.D. 2040—Thirty years have passed since the battle between the Earth and Zentraedi forces changed the lives of both races. On planet Eden, a top-secret project known as "Supernova" is being held to determine U.N. Spacy's next-generation variable fighter. Competing to win the funding are Shinsei Industries' YF-19 and General Galaxy's YF-21. Piloting the YF-21 is Guld Goa Bowman, a half-human, half-Zentraedi. Shinsei receives its new test pilot in the form of the unruly fighter pilot Isamu Dyson, who was once a friend of Guld. Meanwhile, as Isamu and Guld furiously battle to see which of their fighters is superior, a Virturoid Idol named Sharon Apple is to perform her debut concert on Eden. In charge of Sharon is producer Myung Fang Lone, another former friend of Isamu and Guld. When the three meet each other, old disputes spark from a troubled past. Little do they know that their past incidents—along with the Supernova Project and Sharon Apple—will somehow bring them together.

Unaired episode released with the seventh volume of the Blu-ray & DVD. It consists of three short episodes newly written by the manga author Fujiwara Cocoa. Fujiwara also designed a new character called Hana-chan for the episode.

As close encounters of the twisted kind between the residents of the planet Develuke (represented primarily by the female members of the royal family) and the inhabitants of Earth (represented mainly by one very exhausted Rito Yuki) continue to escalate, the situation spirals even further out of control. When junior princesses Nana and Momo transferred into Earth School where big sister LaLa can (theoretically) keep an eye on them, things SHOULD be smooth sailing. But when Momo decides she'd like to "supplement" Rito's relationship with LaLa with a little "sisterly love," you know LaLa's not going to waste any time splitting harems. Unfortunately, it's just about that point that Yami, the Golden Darkness, enters the scene with all the subtleness of a supernova, along with an army of possessed high school students! All of which is certain to make Rito's life suck more than a black hole at the family picnic. Unless, of course, a certain semi-demonic princess can apply a little of her Develukean Whoop Ass to exactly that portion of certain other heavenly bodies! (Source: Sentai Filmworks)