They are the chief villains of the first story arc in every version of the series, and were first introduced in the first chapter of the manga, "Usagi – Sailor Moon", originally published in Japan's Nakayoshi on 28 December 1991.

Though killed by Sailor Venus with the Holy Moon Sword, Beryl is reborn in the 20th century, regaining the memories of her past life upon finding Queen Metaria while traveling to D-Point in the Arctic.

[3]: Act 12  She becomes Queen of the Dark Kingdom, communicating with Metaria while recruiting her reincarnated generals Jadeite, Nephrite, Zoisite, and Kunzite, to find the Silver Crystal.

[5]: Act 7  Beryl is able to summon the reincarnated Prince Endymion, Mamoru Chiba, to her side, as a lifeless thrall after he dies and is revived with a fragment of the Silver Crystal inside him.

[6] In the live-action series, Jadeite and Nephrite are rivals for her affections; Zoisite is more loyal to Endymion than to her, and Kunzite sets his sights on taking Metaria's power for himself.

[8] Similarly, in Shin Densetsu Kourin, Beryl kills the evil King Endymion mud puppet to give Sailor Moon a fighting chance against Galaxia.

During recording, this contrast resulted in occasional fits of giggles among the cast when Han would change from Luna's cute, catlike voice to the deep, evil tones of Beryl.

[5]: Act 7  After Endymion's reincarnated form is captured, Metaria turns the youth into a thrall to retrieve the then powerless Silver Crystal while sacrificing Beryl in the process.

In the DIC English adaptation, the Four Kings of Heaven served as human-like beings from the Negaverse, an alternate dimension of evil, and had only a vague understanding of human ways.

When the Sailor Guardians manage to reach the Four Kings during the former group's assault on D-Point, they regain their full memories before being obliterated by Queen Metaria for outliving their usefulness.

When Jadeite fails for a final time at the airport despite claiming that he found out the identities of the Sailor Senshi, an infuriated Beryl considers it an excuse and condemns him to Eternal Sleep by freezing him in a large crystal.

In the live-action series, Jadeite is totally subservient to Beryl, for which she rewards him with her favor, sending him on missions that range from gathering energy to spying on his fellow warriors to attacking the Sailor Guardians directly.

Establishing himself in an abandoned church, he uses intonation with the stars to detect the "energy potential" of individual people before attacking them when he implants the essence of one of his Monsters into a specific person's object.

Repeatedly humiliated by the Sailor Guardians, and mocked by the other Kings of Heaven, he strives to win Beryl's favor, but she kills her as a demonstration of her power.

He is then reborn in Tokyo as a normal human being with all his memories intact, getting a job at the karaoke parlor and forging a tenuous friendship with Ami Mizuno, who was compassionate toward him when she was Dark Mercury.

Seeking the Silver Crystal, he uses news reports and press releases to make the population of Tokyo help with his search, then resorts to taking their energy when they fail.

The DIC English adaptation of the anime changed Zoisite's gender to female in order to make his relationship with Kunzite more socially acceptable for the 1990s when very few homosexual couples were portrayed in the media.

At one point when Beryl spared Nephrite from Eternal Sleep due to bringing energy despite failing to take out Sailor Moon and Tuxedo Mask, she told Zoisite to remember his position and to focus on finding the Silver Crystal (the DIC dub had Beryl warning Zoisite that she'll be joining Jadeite in Eternal Sleep if he questions her judgement again).

After being killed by Sailor Venus and later revived by the power of Metaria, he ignores Beryl and uses his music to attempt to reach out to Endymion and to restore the memories of their collective past life to his fellow Kings of Heaven.

He defeats the Sailor Guardians at Tokyo Tower and nearly kills Usagi, but Mamoru takes the injury for her, and they are revealed to be Princess Serenity and Prince Endymion.

Kunzite is awakened early on to the memory that Endymion was his master in his previous life, but he feels extreme contempt for the prince, believing he betrayed the Four Kings of Heaven in ages past and left them for dead.

Beryl uses her magic to turn him into a thrall of the Dark Kingdom and has him assume the identity of Endou to aid her in her scheme to locate the Sailor Guardians' base and steal the Silver Crystal.

In Act 20, he kidnaps Ami Mizuno, who at the time is the loneliest and most vulnerable member of the team, and exposes her to Queen Metaria's energies, changing her into an evil alter ego called Dark Mercury.

Kunzite keeps her fairly close, being careful to withdraw her whenever Sailor Moon attempts healing but takes advantage of her newly-sadistic personality by allowing her to attend school and antagonize Usagi.

Baba was portrayed by Mayumi Shintani, while the other unnamed Lemures were played by Ayumi Shimozono, Asuka Yoshidome, Kumiko Saitou, Shiho Tsukagoshi, Moka Kodama, and Miki Shirai.

[37] While reviewing shinto, feminism and anime, author Sarah Reeves considered that Beryl's overall misconduct and strategies are the result of a lack of husband and children.

[39]: 281  However, Drazen later made a later review about Nephrite's death at the hands of Zoisite's monsters and stated that this scene must have been an unexpected development for viewers used to happy endings.

"[41] In her review of the DVD+Blu-ray combo pack of the English dub for Anime News Network, writer Rebecca Silverman compared Zoisite and Kunzite to Jadeite and Nephrite, stating that the former are better strategists than the latter.

In this version, Zoisite's dub is male, and Silverman described voice actor Lucien Dodge's job as "convincingly androgynous, sounding more masculine when the character is angry, which works well.

[44] Regarding Jadeite's demise, Sullivan hoped the writers devoted more time on the confrontation against him instead of the Sailor Guardians tracking him down, since he was supposed to be a formidable opponent.