Question: Who is the playwright who wrote the play that Sakura no Sono's story focuses on?

Context articles: List of Umineko When They Cry episodes
Sakura no Sono
The Gardener's Son
Cardcaptor Sakura
List of Unbalance Unbalance chapters
Yae no Sakura
Susannah
The Cherry Orchard
J. D. Cerna
The Adding Machine

The "Umineko When They Cry" anime television series is based on the sound novel series of the same name by the Japanese dōjin soft maker 07th Expansion.
 The episodes, produced by Studio Deen, are directed by Chiaki Kon, written by Toshifumi Kawase, and features character design by Yoko Kikuchi who based the designs on Ryukishi07's original concept, who also wrote the original story.
 The story focuses on a group of eighteen people on a secluded island for a period of two days, and the mysterious murders that befall most of the people.
 The 26 episodes in the series aired in Japan between July 2 and December 24, 2009 on the Chiba TV broadcasting network and aired on additional stations at later times.
 Six BD and DVD compilation volumes were released in Japan by Geneon Universal Entertainment between October 23, 2009 and March 25, 2010.
 The opening theme is "Katayoku no Tori" (片翼の鳥 , lit.
 "One-Winged Bird") by Akiko Shikata, and the ending theme is "La Divina Tragedia: Makyoku" (la divina tragedia～魔曲～ , lit.
 "The Divine Tragedy: Demonic Song") by Jimang.
Sakura no Sono (櫻の園 , literally "Cherry Blossom Garden") is a Japanese manga series written and illustrated by Akimi Yoshida.
 It was serialized from 1985 to 1986 in Hakusensha's manga magazine LaLa.
 The story focuses on individuals from a drama club that are putting on the play "The Cherry Orchard".
The Gardener’s Son is a screenplay by American writer Cormac McCarthy.
 It is the first published screenplay written by McCarthy, who primarily writes novels but has also written two plays and had four of his novels adapted into feature-length films.
 The story is based around a strange murder in Graniteville, South Carolina in 1876 that is without many details.
 At the request of director Richard Pearce, McCarthy wrote the screenplay for a two-hour episode of the television series "Visions", which was broadcast by PBS on January 6, 1977.
 The story focuses on a young man embittered by the changes in his community due to the capitalist ways of the owner of the town's cotton mill.
 His anger grows until his rage consumes both himself and the families caught up in it.
 The episode was nominated for two Emmy awards and the screenplay has gone on to be published in book form.
Cardcaptor Sakura (Japanese: カードキャプターさくら , Hepburn: Kādokyaputā Sakura ) , abbreviated as CCS and also known as Cardcaptors, is a Japanese "shōjo" manga series written and illustrated by the manga group Clamp.
 The manga was originally serialized in "Nakayoshi" from May 1996 to June 2000, and published in 12 "tankōbon" volumes by Kodansha from November 1996 to July 2000.
 The story focuses on Sakura Kinomoto, an elementary school student who discovers that she possesses magical powers after accidentally freeing a set of magical cards from the book they had been sealed in for years.
 She is then tasked with retrieving those cards in order to avoid an unknown catastrophe from befalling the world.
 A sequel by Clamp titled "" focusing on Sakura in junior high school began serialization in "Nakayoshi" with the July 2016 issue.
"Unbalance Unbalance" is a Korean manhwa series written by Dall-Young Lim and illustrated by Soo-Hyun Lee.
 The series focuses on Jin-Ho Myung, a slacker student in his last year of high school, and Hae-Young Nah, a beautiful young woman in her mid-twenties who is revealed to be Jin-Ho's homeroom teacher.
 The story focuses on the ongoing romantic relationship between the two, as well as other relationships with other girls in Jin-Ho's life as the story progresses.
Yae no Sakura (八重の桜 , Yae's Sakura ) is a 2013 Japanese television series.
 It is the 52nd NHK taiga drama.
 The story focuses on Niijima Yae, who is portrayed by Haruka Ayase.
 Yae is a strong believer in women's rights and the story follows her journey in Japan, during the time it is opened up to Western ideas.
Susannah is an opera in two acts by the American composer Carlisle Floyd, who wrote the libretto and music while a member of the piano faculty at Florida State University.
 Floyd adapted the story from the Apocryphal tale of Susannah and the Elders, though the latter story has a more positive ending.
 The story focuses on 18-year-old Susannah Polk, an innocent girl who is targeted as a sinner in the small mountain town of New Hope Valley, in the Southern American state of Tennessee.
The Cherry Orchard (Russian: "Вишнëвый сад" , "Vishnevyi sad " ) is the last play by Russian playwright Anton Chekhov.
 Written in 1903, it was first published by "Znaniye" (Book Two, 1904), and came out as a separate edition later that year in Saint Petersburg, via A.F. Marks Publishers.
 It opened at the Moscow Art Theatre on 17 January 1904 in a production directed by Konstantin Stanislavski.
 Chekhov described the play as a comedy, with some elements of farce, though Stanislavski treated it as a tragedy.
 Since its first production, directors have contended with its dual nature.
 It is often identified as one of the three or four outstanding plays by Chekhov, along with "The Seagull", "Three Sisters", and "Uncle Vanya".
John Dayton Cerna, often credited as J. D. Cerna, is an American actor and a writer.
 He appeared in the 1988-89 horror film "The Dead Come Home".
 In the 1995 coming-of-age short film "Alkali, Iowa", which is part of "Boys Life 2", the 1997 compilation of short films about gay males, Cerna portrayed Jack Gudmanson, a leading character who is coming to terms of his sexuality and learns about his father's secret past.
 He was a columnist for the LGBT-related newspaper "Washington Blade" in 2002–05.
 He wrote and performed a leading role of his semi-autobiographical play "Not as Cute as Picture", whose story focuses on a "young gay man's pursuit of purpose[,] often obstructed by [crisis] of AIDS," set in 1994.
 The play was nominated in the 14th Annual GLAAD Media Awards (2003) for Outstanding Theatre: Washington D. C.
 He wrote another play "Problem Cat: A Love Story".
The Adding Machine is a 1923 play by Elmer Rice; it has been called "... a landmark of American Expressionism, reflecting the growing interest in this highly subjective and nonrealistic form of modern drama."
 The author of this play takes us through Mr. Zero’s trial, execution, excursion and arrest going into the afterlife.
 During the whole series of this episodic journey Mr. Zero is surprisingly oblivious to his deepest needs, wants and desires.
 The story focuses on Mr. Zero, an accountant at a large, faceless company.
 After 25 years at his job, he discovers that he will be replaced by an adding machine.
 In anger and pain, he snaps and kills his boss.
 Mr. Zero is then tried for murder, is found guilty and hanged.
 He wakes up in a heaven-like setting known as the "Elysian Fields."
 Mr. Zero meets a man named Shrdlu, then begins to operate an adding machine until Lieutenant Charles, the boss of the Elysian Fields, comes to tell Zero that he is a waste of space and his soul is going to be sent back to the earth to be reused.
 The play ends with Zero following a very attractive girl named Hope (who may not actually exist) off stage.