Question: Which of the following writers is regarded as the "Father of the Japanese short story": Ryūnosuke Akutagawa or Andrew Vachss?

Context paragraphs:
Yasushi Akutagawa: Yasushi Akutagawa (芥川 也寸志 , Akutagawa Yasushi , July 12, 1925 — January 31, 1989) was a Japanese composer and conductor.  He was born and raised in Tabata, Tokyo.  His father was Ryūnosuke Akutagawa.

Ryūnosuke Akutagawa: Ryūnosuke Akutagawa (芥川 龍之介 , Akutagawa Ryūnosuke , 1 March 1892 – 24 July 1927) was a Japanese writer active in the Taishō period in Japan.  He is regarded as the "Father of the Japanese short story" and Japan's premier literary award, the Akutagawa Prize, is named after him.  He committed suicide at the age of 35 through an overdose of barbital.

Hell Screen: Hell Screen (地獄変 , Jigokuhen ) is a short story written by Japanese writer Ryūnosuke Akutagawa.  It was originally published in 1918 as a serialization in two newspapers.  It was later published in a collection of Akutagawa short stories, "Akutagawa Ryūnosuke zenshū".

A Note to a Certain Old Friend: A Note to a Certain Old Friend (或旧友へ送る手記 , Aru Kyūyū he Okuru Shuki ) is the title of the suicide note left by the famed Japanese short story writer, Ryūnosuke Akutagawa.  This was the last thing Akutagawa wrote before he committed suicide at the age of 35 in 1927.  The letter was addressed to his close friend and fellow writer Masao Kume.

Akutagawa Prize: The Akutagawa Prize (芥川龍之介賞 , Akutagawa Ryūnosuke Shō ) is a Japanese literary award presented semi-annually.  It was established in 1935 by Kan Kikuchi, then-editor of "Bungeishunjū" magazine, in memory of author Ryūnosuke Akutagawa.  It is currently sponsored by the Society for the Promotion of Japanese Literature, and is awarded in January ('E' in the list, below) and July ('L' in the list below) to the best serious literary story published in a newspaper or magazine by a new or rising author.

The Nose (Akutagawa short story): "The Nose" (鼻 , Hana ) is a satirical short story by Akutagawa Ryūnosuke based on a thirteenth-century Japanese tale from the "Uji Shūi Monogatari".  "The Nose" was Akutagawa’s second short story, written not long after "Rashōmon".  It was first published in January 1916 in the Tokyo Imperial University student magazine Shinshichō and later published in other magazines and various Akutagawa anthologies.  The story is mainly a commentary on vanity and religion, in a style and theme typical to Akutagawa’s work.

Dragon: the Old Potter's Tale: "Dragon: the Old Potter’s Tale" (龍 , Ryū ) is a short story by Ryūnosuke Akutagawa.  It was first published in a collection of Akutagawa short stories, "Akutagawa Ryūnosuke zenshū".  The story is based on a thirteenth-century Japanese tale, with Akutagawa’s Taishō literary interpretations of modern psychology and the nature of religion.

Rashomon: Rashomon (羅生門 , Rashōmon ) is a 1950 Japanese period film directed by Akira Kurosawa, working in close collaboration with cinematographer Kazuo Miyagawa.  It stars Toshiro Mifune, Machiko Kyō, Masayuki Mori, and Takashi Shimura.  While the film borrows the title and setting from Ryūnosuke Akutagawa's short story "Rashōmon", it is actually based on Akutagawa's short story "In a Grove", which provides the characters and plot.

Autumn Mountain: Autumn Mountain (秋山 , Akiyama ) is a 1921 short story by Japanese writer Ryūnosuke Akutagawa.  Akutagawa first published the story when he was twenty-nine.  The story tells the tale of a painting, supposed to be the greatest ever made.  However, when the speaker sees the painting, it does not meet the expectations of the promised masterpiece of unparalleled beauty.  However, even though the speaker does not know if the painting actually exists, he realizes that he can see the beauty in his mind.  In the short story, Akutagawa deals with the subjects of truth and beauty.

Andrew Vachss: Andrew Henry Vachss (born October 19, 1942) is an American crime fiction author, child protection consultant, and attorney exclusively representing children and youths.

Supporting paragraphs: Ryūnosuke Akutagawa Andrew Vachss
Answer: Ryūnosuke Akutagawa