Beyond the Boundary(Japanese: 境界の彼方,Hepburn: Kyōkai no Kanata?) is a Japanese light novel series written by Nagomu Torii, with illustrations by Tomoyo Kamoi. The work won an honorable mention in the Kyoto Animation Award competition in 2011. Kyoto Animation has published three volumes since June 2012. An anime television series adaptation, produced by Kyoto Animation, aired in Japan between October and December 2013. An original video animation episode was released in July 2014. A two-part anime film project will premiere in March and April 2015.
One day, high school student Akihito Kanbara instinctively goes to save his fellow schoolmate, Mirai Kuriyama, from committing suicide. Following his pleas, Mirai suddenly stabs Akihito with a sword formed out of her own blood and is shocked to discover that Akihito is an immortal "half-youmu"—the offspring of a supernatural creature called a youmu and a human. After learning that Mirai is a Spirit World Warrior (異界士,Ikaishi?)—specialists who protect humans from being affected by youmu—and the last surviving member of her spirit hunting clan, their lives become intertwined as Akihito seeks to help Mirai gain the confidence to kill youmu so that she may stop attempting to kill him as practice.
In Beyond the Boundary, youmu (妖夢,yōmu?, alt. Dreamshade) are supernatural creatures that appear throughout the series and can only be seen by those with a supernatural affinity. They are said to be the physical materialization of human animosity such as negative emotions including hatred, jealousy and malice and therefore as long as humans exist, youmu will continue to exist. They can exist in many types of shapes and forms with some even having a human appearance. There are also rare cases when a youmu and a human mate and produce offspring called Half-Youmu (半妖,Han-Yō?, "Half-Shade"). Most youmu are relatively docile and coexist with humans without them even aware of their presence. However, there are times when a youmu's behavior upsets the balance, so the Spirit World Warriors are sent in to kill them. Upon death, a youmu produces a Youmu Stone (妖夢石,Yōmu Ishi?, alt. Dreamshade Stone) which can be appraised and traded, hence providing a source of income for a Spirit World Warrior.
Akihito is a second-year high school student with short blonde hair who is an immortal half-youmu, the offspring of a youmu and a human. He has the ability to heal quickly from any wound albeit still experiencing pain. Due to this Mirai uses him as practice to help overcome her fear of killing youmus. He is a member of the Literary Club. He has a preference for glasses, as shown by his spontaneous compliments to Mirai as well as being disdainfully teased for it by Mitsuki. If Akihito's physical human body finds itself in a severe weakened state, his dormant youmu half emerges, physically changing his body into a hideous feral appearance which then proceeds to go on a rampage. Akihito's youmu half is extremely powerful, able to easily overwhelm supernatural cages and barriers that attempt to contain it in addition to having enough destructive force to physically devastate whatever landscape surrounds it. Akihito implies that because of his youmu half, the Nase clan are not exactly his friends but instead people who are tasked with watching him should his youmu half ever go berserk, and killing him if necessary. Following a youmu transformation, Akihito falls into a state of depression due to almost killing Hiroomi in a past rampage. Akihito's youmu half holds the greatest destructive power of all youmu and is referred to as "Beyond the Boundary".
Mirai is a first-year high school student with short, strawberry-blonde hair styled into a bob, and wears red-rimmed glasses, leading Akihito to call her a 'bespectacled beauty', much to her dismay. She has the ability to manipulate blood, which is unique even within the scope of the Spirit World. Overuse of her ability results in severe anemia while at the same time it causes her to feel isolated and seemingly attempts suicide by jumping off the roof of the high school until she is saved by Akihito. She is apparently hated anywhere she goes as shown by her blog and Twitter being constantly flamed, which is due to her constantly posting about the misfortunes in her life. She has a habit of using the phrase, "How unpleasant" (「不愉快です」,"Fuyukai desu"?) to describe most situations, particularly at remarks made by Akihito. Despite her cursed blood lineage, she was adopted by the Inami clan and befriended their youngest daughter, Yui Inami whom she killed out of fear after Yui was possessed by the Hollow Shadow—an act of which Mirai is deeply regretful and hence gave root to her fear of killing. Her signature weapon is a carmine colored sword formed out of her blood.
Mitsuki is a second-year high school student with long, silky black hair. She is Akihito's childhood friend. She is the President of the Literary Club and has a habit of constantly teasing Akihito. Her clan governs Spirit World Warriors in their area. Izumi instilled in her the belief that Spirit World Warriors are to be alone all their life, due to their duties and hence resulted in Mitsuki missing experiences with her peers while growing up. She has a rodent-like youmu called "Yakiimo" as a familiar. Like her brother, Mitsuki is capable of setting up cages.
Hiroomi is a third-year high school student who is also Mitsuki's brother. He has black hair in a bowl-cut and wears a scarf at all times due to his supernatural powers that make him cold. He is also a member of the Literary Club. Hiroomi likes having his sister call him "Big Brother", and also has a habit of teasing Akihito and affectionately calls him "Akkey". He is proficient in setting up cages or barriers that prevent youmu from entering a protected area. His supernatural abilities make him extremely sensitive to the cold which not only causes him to constantly wear a scarf and also warm his fingers in Akihito's armpits much to the latter's annoyance. His back is severely scarred due to having to restrain Akihito's youmu rampage in the past, which almost resulted in his death.
A rather skilled Spirit World Warrior. She is usually referred to as "Nino-san" and works as a teacher at Nagatsuki High School, in addition to Spirit Hunting. Despite her beauty, she always finds herself turned down by men.
Akihito's mother and a Spirit World Warrior. She is constantly traveling and sends Akihito a postcard to check up on him every so often. Akihito describes her as being a "free-spirited" avant-garde thinker in addition to possessing an eccentric personality and is thus ashamed of her child-like behavior. This is shown during Akihito's elementary school's Parents' Day when she sat at a student's desk while wearing a panda costume and participated in the class.
The eldest daughter of the Nase clan. She usually has a calm demeanor despite having a malicious undertone. She has the viewpoint that youmu are no different from crops or farm animals and exist solely to provide her clan with a livelihood. Like the rest of her clan, Izumi is proficient in setting up barriers. She possesses a type of freezing ability while her signature weapon is a dual-tipped spear. She has a past connection with Miroku and also harbors a youmu within her body—which she tries to keep from the rest of her clan.
A silver-haired girl who was pursued during the Spirit World Warrior-slaying incidents. Her signature weapons include an automatic pistol and revolver. She also possesses the ability to suppress the power of an Interrogation Officer. She had an incident in the past with Miroku.
An interrogation officer from the Spirit World Warriors' Observation Department. He has the ability to instantly kill a youmu by simply focusing on it. He harbors a youmu within his own body, granting him special abilities.
An appraiser of youmu. Her appraising business is camouflaged as a photo shop to normal humans. Her true form is that of a powerful multi-tailed fox-like youmu but usually takes the appearance of a human. She is also capable of setting up cages and barriers.
An anime original character, Sakura is the younger sister of Yui Inami. She hates Mirai for Yui's death and tries to kill the former as an act of revenge, but later realizes her true feelings for Mirai were clouded and forgives her. She has a tendency to be lazy at times. Sakura's spiritual powers are practically non-existent hence she fought using a spear courtesy of Miroku which absorbed the power of youmu stones.
Sophomore at Nagatsuki High School. She wears a large ribbon on her head. Her signature phrase is "Hey!".
Beyond the Boundary began as a light novel series written by Nagomu Torii, with illustrations provided by Tomoyo Kamoi. Torii entered the first novel in the series into the second Kyoto Animation Award contest in 2011, and it won an honorable mention in the novel category. The studio later published the first volume on June 9, 2012, and three volumes have been released as of October 2, 2013.
An anime television series adaptation, produced by Kyoto Animation and directed by Taichi Ishidate, began airing on October 2, 2013. The opening theme is "Kyōkai no Kanata" (境界の彼方?) by Minori Chihara and the ending theme is "Daisy" sung by Stereo Dive Foundation. The series is also being simulcast on Crunchyroll. The anime has been licensed by Sentai Filmworks in North America for streaming and home video release in 2015. Three original net animation episodes of a short series titled Beyond the Boundary Idol Trial!(「きょうかいのかなた アイドル裁判!,Kyōkai no Kanata Aidoru Saiban!?) were released between November 18 and December 16, 2013, on the official website via YouTube. Two additional Idol Trial episodes were released on DVD and Blu-ray Disc along with the first three and a full-length original video animation episode on July 2, 2014.
A two-part film project titled Gekijōban Kyōkai no Kanata: I'll Be Here(劇場版 境界の彼方 -I'll Be Here-,Beyond the Boundary the Movie: I'll Be Here)?) will be produced by Kyoto Animation and directed by Taichi Ishidate. The first film, Kako-hen(過去篇,The Past?), will be released on March 14, 2015. The second film, Mirai-hen(未来篇,The Future?), will be released on April 25, 2015. Kako-hen will recount the events of the television series, and Mirai-hen will be an original story set one year after the end of the television series.