Slice of life is a depiction of mundane experiences in art and entertainment.  In theater, slice of life refers to naturalism, while in literary parlance it is a narrative technique in which a seemingly arbitrary sequence of events in a character's life is presented, often lacking plot development, conflict, and exposition, as well as often having an open ending.
In theatrical parlance, the term slice of life refers to a naturalistic representation of real life, sometimes used as an adjective, as in "a play with 'slice of life' dialogues". The term originated between 1890 and 1895 as a calque from the French phrase tranche de vie, credited to the French playwright Jean Jullien (1854–1919). 
Jullien introduced the term not long after a staging of his play The Serenade, as noted by Wayne S. Turney in his essay "Notes on Naturalism in the Theatre":
The Serenade was introduced by the Théâtre Libre in 1887. It is a prime example of rosserie, that is, plays dealing with corrupt, morally bankrupt characters who seem to be respectable, "smiling, smiling, damned villains..." Jullien gave us the famous apothegm defining naturalism in his The Living Theatre (1892): "A play is a slice of life put onstage with art." He goes on to say that "...our purpose is not to create laughter, but thought." He felt that the story of a play does not end with the curtain, which is "only an arbitrary interruption of the action which leaves the spectator free to speculate about what goes on beyond your expectation..." 
During the 1950s, the phrase was commonly used in critical reviews of live television dramas, notably teleplays by JP Miller, Paddy Chayefsky,  and Reginald Rose.  At that time, it was sometimes used synonymously with the term "kitchen sink realism", adopted from British films and theatre.
In 2017, screenwriter and scholar Eric R. Williams identified slice-of-life films as one of eleven super-genres in his screenwriters' taxonomy, claiming that all feature-length narrative films can be classified by these super-genres. The other ten super-genres are action, crime, fantasy, horror, romance, science fiction, sports, thriller, war, and western.  Williams identifies the following films as some examples of films in the slice-of-life super-genre: Boyhood, Captain Fantastic, Fences, Moonlight, The Terminal and Waitress.  According to his taxonomy, drama and comedy are identified as film "types", not super-genres. 
In literary parlance, the term "slice of life" refers to a storytelling technique that presents a seemingly arbitrary sample of a character's life, which often lacks a coherent plot, conflict, or ending.  The story may have little plot progress and often has no exposition, conflict, or dénouement, but rather has an open ending. A work that focuses on a minute and faithful reproduction of some bit of reality, without selection, organization, or judgment, and where every small detail is presented with scientific fidelity, is an example of the "slice of life" novel.  This is demonstrated in the case of Guy de Maupassant's novel A Woman's Life, which told the story of a woman who transformed an unrequited love for her husband into a pathological affection towards her son. 
In the United States, slice of life stories were given particular emphasis by the Chicago school at the end of the 19th century, a period when the novel and social sciences became different systems of discourse.  These produced literary texts by researcher-authors that were written to represent the subject's stories and sentiment-free social realism using the language of ordinary people.  It formed part of the late 19th- and early 20th-century naturalism movement in literature, which was inspired by the adaptation of principles and methods of social sciences such as the Darwinian view of nature.  The movement was an extension of realism, presenting the faithful representation of reality without moral judgment.  Some authors, particularly playwrights, used it by focusing on the "underbelly of life" to expose social ills and repressive social codes with the aim of shocking the audience and motivating them towards social reform. 
Slice of life anime and manga are narratives "without fantastical aspects, which [take] place in a recognisable, everyday setting, such as a suburban high school, and which [focus] on human relationships that are often romantic in nature."  The genre favors "the creation of emotional ties with the characters."  The popularity of slice of life anime started to increase in the mid-1980s.  Masayuki Nishida writes that slice of life anime and manga can still involve elements of fantasy or a fantastical world: "Fantasy is sometimes used as a means to express the “reality” of human beings under certain possible conditions."  Robin E. Brenner's 2007 book Understanding Manga and Anime holds that in anime and manga, "slice of life" is a genre that is more akin to melodrama than drama, bordering on absurd due to the large numbers of dramatic and comedic events in very short spans. The author compares it to teen dramas such as Dawson's Creek or The O.C. This genre claims a large section of the Japanese manga market and usually focuses on school and interpersonal relationships. 
One subgenre of slice of life in anime and manga is kūki-kei (空気系, "air type"), also called nichijō-kei (日常系, "everyday type"). In this genre, "descriptions of deep personal relationships or fully fledged romantic relationships are deliberately eliminated from the story in order to tell a light, non-serious story that focuses on the everyday lives and conversations of the bishōjo characters."  This relies on a "specificity of place," as well as a "peaceful, heartwarming sense of daily life."  The nichijō-kei genre developed from yonkoma manga, and includes works like Azumanga Daioh , K-On! , and Hidamari Sketch .  Takayoshi Yamamura argues that the rise in popularity of this subgenre in the mid-2000s enabled the increasing popularity of media tourism to locations featured in anime. 
Stevie Suan writes that slice of life anime such as Azumanga Daioh often involve exaggerated versions of the "conventionalized expressions" of the medium, such as "white circles for eyes in times of trouble, shining, vibrant big eyes to depict overflowing emotion, sweat drops, animal teeth, and simplistic human rendering." 
A comedy film is a category of film which emphasizes humor. These films are designed to make the audience laugh through the amusement. Films in this style traditionally have a happy ending. Comedy is one of the oldest genres in the film—and derived from the classical comedy in theatre. Some of the earliest silent films were comedies, as slapstick comedy often relies on visual depictions, without requiring sound. To provide drama and excitement to movies, live music was played in sync with the action on the screen, by pianos, organs, and other instruments. When sound films became more prevalent during the 1920s, comedy films grew in popularity, as laughter could result from burlesque situations but now also dialogue.
A film genre is a stylistic or thematic category for motion pictures based on similarities either in the narrative elements, aesthetic approach, or the emotional response to the film.
The Western is a genre of fiction set in the American frontier and commonly associated with folk tales of the Western United States, particularly the Southwestern United States, as well as Northern Mexico and Western Canada.
Azumanga Daioh is a Japanese yonkoma comedy manga series written and illustrated by Kiyohiko Azuma. It was serialized from February 1999 to May 2002 in the monthly magazine Dengeki Daioh by MediaWorks; three additional chapters were published in Shogakukan's Monthly Shōnen Sunday in May 2009 to celebrate the manga's tenth anniversary. The manga was first released in English by ADV Manga, and later re-issued by Yen Press.
Crime films, in the broadest sense, is a film genre inspired by and analogous to the crime fiction literary genre. Films of this genre generally involve various aspects of crime and its detection. Stylistically, the genre may overlap and combine with many other genres, such as drama or gangster film, but also include comedy, and, in turn, is divided into many sub-genres, such as mystery, suspense or noir.
Kiyohiko Azuma is a Japanese manga artist. From 1999 to 2002, he authored the yonkoma comedy manga series Azumanga Daioh, which was later adapted as an anime series by J.C.Staff. In 2003, he began Yotsuba&!, a slice-of-life manga series about the adventures of a five-year-old girl; it is serialized in the monthly magazine Dengeki Daioh.
Yotsuba&! is a Japanese manga series written and illustrated by Kiyohiko Azuma, the creator of Azumanga Daioh. It has been serialized since January 2003 in the monthly magazine Dengeki Daioh by ASCII Media Works, formerly MediaWorks, and has since been collected into 15 tankōbon volumes. It depicts the everyday adventures of a young girl named Yotsuba as she learns about the world around her, guided by her adoptive father, their neighbors, and their friends. Several characters in Yotsuba&! were previously featured in a one-shot manga by Azuma called "Try! Try! Try!" The phrase Yotsuba to means "Yotsuba and," a fact reflected in the chapter titles, most of which take the form "Yotsuba and [something]."
Romance films, romance movies, or ship films involve romantic love stories recorded in visual media for broadcast in theatres or on television that focus on passion, emotion, and the affectionate romantic involvement of the main characters. Typically their journey through dating, courtship or marriage is featured. These films make the search for romantic love the main plot focus. Occasionally, romance lovers face obstacles such as finances, physical illness, various forms of discrimination, psychological restraints or family resistance. As in all quite strong, deep and close romantic relationships, the tensions of day-to-day life, temptations, and differences in compatibility enter into the plots of romantic films.
Doki Doki School Hours is a Japanese four-panel manga series by Tamami Momose. The manga was serialized in Manga Life and published by Takeshobo from 1997 to 2013.
Mecha anime and manga, known in Japan as robot anime and robot manga, are anime and manga that feature robots (mecha) in battle. The genre is broken down into two subcategories; "super robot", featuring super-sized, implausible robots, and "real robot", where robots are governed by realistic physics and technological limitations.
Moyasimon: Tales of Agriculture, known in Japan as Moyashimon (もやしもん), is a Japanese manga series by Masayuki Ishikawa. It was serialized in Kodansha's seinen magazine Evening from July 2004 to June 2013 and moved to the magazine Monthly Morning Two, where it concluded in January 2014. The series follows Tadayasu Sawaki, a first-year college student at an agricultural university, who has a unique ability to see and communicate with microorganisms. Del Rey Manga licensed the manga, but only released two volumes in English in North America. An 11-episode anime television series adaptation, animated by Shirogumi and Telecom Animation Film, aired between October and December 2007 on Fuji TV's Noitamina programming block. An 11-episode live action adaptation was aired on Noitamina between July and September 2010. An 11-episode animated second season titled Moyasimon Returns aired from July to September 2012.
In film and television, drama is a category or genre of narrative fiction intended to be more serious than humorous in tone. Drama of this kind is usually qualified with additional terms that specify its particular super-genre, macro-genre, or micro-genre, such as soap opera, police crime drama, political drama, legal drama, historical drama, domestic drama, teen drama, and comedy-drama (dramedy). These terms tend to indicate a particular setting or subject-matter, or else they qualify the otherwise serious tone of a drama with elements that encourage a broader range of moods. To these ends, a primary element in a drama is the occurrence of conflict—emotional, social, or otherwise—and its resolution in the course of the storyline.
In anime and manga, the term "LGBTQ themes" includes lesbian, gay, bisexual and transgender material. Outside Japan, anime generally refers to a specific Japanese-style of animation, but the word anime is used by the Japanese themselves to broadly describe all forms of animated media there. According to Harry Benshoff and Sean Griffin, the fluid state of animation allows flexibility of animated characters to perform multiple roles at once. Manga genres that focus on same-sex intimacy and relationships resulted from fan work that depicted relationships between two same-sex characters. This includes characters who express their gender and sexuality outside of hetero-normative boundaries. There are also multiple sub genres that target specific consumers and themes: yaoi, yuri, shoujo-ai, shonen-ai, bara, etc. LGBT-related manga found its origins from fans who created an "alternative universe" in which they paired their favorite characters together. Many of the earliest works that contained LGBT themes were found in works by dōjinshi who has specifically written content outside the regular industry. The rise of yaoi and yuri was also slowed due to censorship laws in Japan that make it extremely hard for Japanese manga artists ("mangakas") and others to create work that is LGBT themed. Anime that contained LGBTQ content was changed to meet international standards. However, publishing companies continued to expand their repertoire to include yuri and yaoi, and conventions were created to form a community and culture for fans of this work.
Isekai is a genre of speculative fiction—both portal fantasy and science fiction are included. It includes novels, light novels, films, manga, anime and video games that revolve around a displaced person or people who are transported to and have to survive in another world, such as a fantasy world, virtual world, or parallel universe. Isekai is one of the most popular genres of anime, and Isekai stories share many common tropes – for example, a powerful protagonist who is able to beat most people in the other world by fighting. This plot device typically allows the audience to learn about the new world at the same pace as the protagonist over the course of their quest or lifetime. If the main characters are transported to a game-like world, the genre can overlap with LitRPG.
Sports manga is a genre of Japanese manga and anime that focuses on stories involving sports and other athletic and competitive pursuits. Though Japanese animated works depicting sports were released as early as the 1920s, sports manga did not emerge as a discrete category until the early 1950s. The genre achieved prominence in the context of the post-war occupation of Japan, and gained significant visibility during and subsequent to the 1964 Summer Olympics in Tokyo. Noted as among the most popular genres of manga and anime, sports manga is credited with introducing new sports to Japan, and popularizing existing sports.
Iyashikei (癒し系) is a genre specific to Japanese works, primarily manga and anime. It is a sub-genre of slice of life, portraying characters living out peaceful lives in calming environments, and is intended to have a healing effect on the audience. The word iyashikei could mean "healing type" or just "healing" in Japanese. Shaenon K Garrity of Otaku USA wrote that in iyashikei works, "the focus is less on character and plot, more on worldbuilding and creating an immersive visual setting".