故事以主角的第一人称进行，“我”（浅沼晋太郎 配音）是京都大学的一名三年级生，原本期待着有一个玫瑰色多姿多彩的大学生活，希望自己能交上飘逸黑长发的漂亮女朋友。然而事与愿违，主人公经历了一场失败的恋爱，身边的朋友也少得可怜。主人公唯一的朋友小津（吉野裕行 配音），长相像一只妖怪，以捉弄情侣为乐。主人公常常唾弃小津，却离不开他。随后主人公认识了师妹明石（坂本真绫 配音），她是个性格冷淡的黑发少女。 正是因为自己当初选择了网球部，才导致大学两年如此失败，于是“我”假想如果自己入学时选择了另外一个社团，会不会经历另外一种截然不同的大学生活呢？本作从平行时空的角度，围绕着主人公重新从大一新生选择社团开始，选择了各种各样不同社团，发展出不一样的青春故事。

物語の締めくくりとも言える、原作の最後に描かれた「空の境界」を完全新作にて映像化！劇場版「空の境界」の全てを集めたBD-BOXも同日発売！ ■ STAFF 原作：奈須きのこ「空の境界」(講談社ノベルス) キャラクター原案：武内崇 キャラクターデザイン・作画監督：須藤友徳／高橋タクロヲ／小船井充 脚本：平松正樹（ufotable） 音楽：梶浦由記 アニメーション制作：ufotable ■CAST 両儀式　：坂本真綾 黒桐幹也 ：鈴村健一

January 1999: Apprentice mage Azaka Kokutou, Mikiya's younger sister, has been ordered by her mentor, Touko Aozaki, to investigate a certain incident in which fairies steal the memories of students at Azaka's school, Reien Academy. Azaka launches an investigation with the help of Shiki.

2008 anime film by Takayuki Hirao

June 1998: After spending two years in a coma caused by a traffic accident, Shiki Ryougi awakens with amnesia. She is visited by Touko Aozaki, a wizard and proprietor of a studio called Garan no Dou. Shiki has lost not only the memory of her accident, but also any real sense that she's even alive. Strangely, enigmatic beings begin to attack her...

In February 1999, a string of murders has Shiki Ryougi and Mikiya Kokutou on edge. These crimes share a disturbing resemblance to a similar set of homicides from 1995, when Shiki and Mikiya first met, and awaken a dark, murderous desire that has laid dormant within Shiki's soul ever since then.

July 1998 - After a group of delinquents is found dead in their hangout place with all their limbs twisted and torn off, Aozaki Touko receives a request to find the murderer and asks Shiki for help. The main suspect is Asagami Fujino; a girl who was the boys' plaything until recently, who Shiki believes to be "one of her kind".

August 1995: Mikiya first meets Shiki in a white kimono during a snowing day. Later on, at the high school freshmen ceremony, Mikiya sees Shiki in the crowd and chases after her, introducing himself to her. But Shiki hides a big secret: A wave of bizarre murders occur around many loose ends, and no suspects. there are still many questions: Who to believe? Who is the murderer? What is the secret of Shiki? and especially: Who is SHIKI?

2007 film by Ei Aoki