Set primarily in New York City in the 1980s, the series follows street gang leader Ash Lynx as he uncovers a criminal conspiracy involving "banana fish", a mysterious drug that brainwashes its users.

The visual and narrative style of Banana Fish, characterized by realist artwork and action-oriented storytelling, represented a significant break from then-established shōjo manga conventions of highly stylized illustration and romantic fantasy-focused stories.

Its depictions of homoeroticism in this mature, action-oriented context were particularly influential on the boys' love (male-male romance) genre of manga.

The anime adaptation aired on Fuji TV's Noitamina programming block and is syndicated globally on Amazon Prime Video, which simulcast the series during its original broadcast run.

Seventeen-year-old street gang leader Ash Lynx cares for his older brother Griffin, a Vietnam War veteran left in a vegetative state following a traumatic combat incident in which he fired on his own squadron and uttered the words "banana fish".

Ultimately, Golzine is killed in a climactic battle, his government co-conspirators are exposed as participants in his child sex trafficking ring, and all evidence of the banana fish project is destroyed.

[4] The film, which depicts the relationship between a con man and a male hustler in New York City, had a profound impact on Yoshida, and influenced her to create works that replicated its themes of close spiritual and fraternal bonds between men.

[4] Owing to the influence of Midnight Cowboy, Yoshida sought to create Banana Fish as story focused on an emotionally intense relationship between two characters, who became Ash and Eiji.

[3] Writer and translator Frederik L. Schodt notes that while Yoshida's works adhere to certain conventions of shōjo manga as textual and subtextual homoeroticism, she at the same time adopts "a completely masculine art style, eschewing flowers and bug eyes in favor of tight bold strokes, action scenes, and speed lines".

[10] Despite her lack of fixed composition for the story, Yoshida intended from the earliest stages of the series' development to have Banana Fish conclude with Ash's death.

[13] North American publisher Viz Media serialized an English-language translation of Banana Fish as a launch title for its manga magazine Pulp beginning in 1998.

[63] Banana Fish was adapted into a 24-episode anime series produced by MAPPA and directed by Hiroko Utsumi, which aired on Fuji TV's Noitamina programming block and Amazon Prime Video from July 5 to December 20, 2018.

[79] Banana Fish would come to represent a shift for depictions of homosexuality in shōjo manga, towards older protagonists and realist writing and artwork, and away from the schoolboy romances and melodramas that had previously defined the genre.

[3] Despite Banana Fish's influence and prominence as a manga depicting homosexuality, the central relationship between Ash and Eiji is never rendered as overtly romantic or sexual.

[78] Thompson considers several potential explanations for the largely subtextual nature of Ash and Eiji's relationship, including Yoshida's stated desire to focus on the emotional connection between the characters, that Yoshida did not wish to risk eroticizing the manga's themes of rape by depicting a romantic or sexual relationship, and the potential influence of manga censorship codes in limiting displays of same-sex romance and sex.

Ash embodies typically masculine agency in his position as a leader of a street gang, but is frequently feminized though the rape he suffers at the hands of men.

[85] Thus, through Ash and Eiji's struggles, the ostensibly female reader is able to "escape from Japanese reality"[86] and "resist the pressures of a highly hierarchical gender and sexual system".

[86] Beyond its American setting and characters, Banana Fish features frequent allusions to American literature:[91] Blanca's character arc is drawn from Ernest Hemingway's Islands in the Stream, Ash compares his life to Hemingway's The Snows of Kilimanjaro,[89] and the title of the series itself is a reference to J. D. Salinger's short story "A Perfect Day for Bananafish".

[92] Critic Hisayo Ogushi considers a less allegorical explanation, noting that the protagonist of Salinger's story commits suicide after he envisions the bananafish, just as characters in the manga lose control of themselves after they are given the banana fish drug.

[89] The action-oriented plot of Banana Fish, characterized by frequent fight scenes, multi-chapter action set pieces, and the extensive use of speed lines, represented a break from the typical visual and narrative conventions of shōjo manga.

[4] Violence and its dehumanizing effects recur as a major theme throughout the series, as character struggle to reconcile their humanity with the violent acts they commit and endure.

[94] While Yoshida had published several manga titles prior to Banana Fish, the series became her most critically and commercially successful work, and "cemented her status as a great creator".

[11] Though Banana Fish was published and marketed as a shōjo manga, its dense plot, heavy dialogue, and extensive action sequences led it to attract a significant crossover audience of male and adult female readers;[2][13][c] Schodt identifies the series as "one of the few girls' manga a red-blooded Japanese male adult could admit to reading without blushing".

[96] Banana Fish is the favorite manga of Japanese musician Gackt – the artist claims to have read the series over one hundred times – and inspired the song "Asrun Dream" on his debut album Mars.

[97][98] Japanese tourism company Kinki Nippon Tourist Kanto offered a New York City tour featuring stops at locations featured in the series and a guided audio tour narrated by Yuma Uchida and Kenji Nojima, who respectively voice Ash and Eiji in the anime adaptation of Banana Fish, performing in-character.