A young Taiwanese assassin codenamed Glass Heart committed suicide by jumping off a building, and her heart was pierced by metal fence. Miraculously, her life was saved by heart transplantation. During her recovery she began to experience strange dreams, which lead her to Japan looking for the donor of her heart, who happens to be Kaori Makimura, former partner of City Hunter Ryo Saeba. The author mentioned in the first tankoubon volume that Angel Heart only shares the same characters of City Hunter but not its continuation. The events are all parallel universe, therefore it has nothing to do with City Hunter. (Source: Wikipedia)

In class 3-3 of Yomiyama North Junior High, transfer student Kouichi Sakakibara makes his return after taking a sick leave for the first month of school. Among his new classmates, he is inexplicably drawn toward Mei Misaki—a reserved girl with an eyepatch whom he met in the hospital during his absence. But none of his classmates acknowledge her existence; they warn him not to acquaint himself with things that do not exist. Against their words of caution, Kouichi befriends Mei—soon learning of the sinister truth behind his friends' apprehension. The ominous rumors revolve around a former student of the class 3-3. However, no one will share the full details of the grim event with Kouichi. Engrossed in the curse that plagues his class, Kouichi sets out to discover its connection to his new friend. As a series of tragedies arise around them, it is now up to Kouichi, Mei, and their classmates to unravel the eerie mystery—but doing so will come at a hefty price.

Special episode included in the Blu-ray Box of Ano Natsu de Matteru.

In the Binfield Kingdom Chronicle, it is said that there was once a small, peaceful country called the Kingdom of Winfield, whose king and royal family possessed great white wings. Hamura Shou is newly enrolled at Yuusei Academy. After hearing about a student named Misonou Kai from the headmaster, Shou comes to believe that Kai is his younger twin brother, who he was separated from when he was younger. However, after a mysterious earthquake, Shou is suddenly carried into another world with two other students. It is in this new world that, after being attacked by a monster, Shou suddenly unleashes great, white wings.