The Guardian Goddess of Planeptune. Her natural cheerfulness, positivity, and needlessly high-tension personality remain unchanged even inside an online game. She possesses a mysterious charm that can shatter any adversity or serious atmosphere. She calls Histoire "Histy." She calls Arfoire "Old Hag." She hates eggplants; she believes eggplants are not meant for human consumption. Nepgear's older sister. She loves pudding and is a regular at the pudding shop in Planeptune. When she wins, she says "Total victory!" Height: 146cm, Weight: 38kg, B73-W54-H76 (A-cup), apparent age: 14 (smaller than average). Her in-game class is Paladin. An all-rounder who can handle physical attacks, magic attacks, and healing.

The Guardian Goddess of Leanbox. She wants to make Nepgear her own little sister. She speaks in an elegant, refined manner (polite/feminine). She has a mature appearance and is a soft-spoken, older-sister type. However, she is secretly a hardcore gamer and a fujoshi. Her private room is overflowing with otaku goods. Since this stage is her beloved online game world, she is secretly aiming for the protagonist's spot. She is the only one among the Goddesses without a sister, so whenever she finds a girl she likes, she immediately tries to scout them into being her sister. Height: 163cm, Weight: 48kg, B93-W61-H87 (F-cup), apparent age: 18. Her in-game class is Enchanter. She is the only member with attribute-buffing skills, making her a hybrid type who can participate in both healing and attacking.

The Guardian Goddess of Lastation. She has a serious, elite disposition and tries to handle everything alone, but she is a tsundere who can't be honest with those close to her. Due to this personality, she is often suspected of being a "loner," but since she has friends to play games with, she is definitely not a loner. Definitely. Though she hides it from those around her, her hobby is cosplay, and she researches costumes even within "4 Goddesses Online." Uni's older sister. Height: 158cm, Weight: 43kg, B83-W56-H82 (C-cup), apparent age: 16. Her in-game class is Black Knight. An attacker type with high power who possesses only skills specialized for close-quarters combat.

The Guardian Goddess of Lowee. Usually quiet, but when stress builds up to the limit, she snaps and undergoes a total personality shift, becoming uncontrollable. Her hobby is reading, and she occasionally enters her self-published novels into conventions incognito, though they don't sell very well. She seems to be looking for material for a new story while playing "4 Goddesses Online." Rom and Ram's older sister. Unlike the other Goddesses, she has a complex about her chest remaining small even after transformation, so she gets furious if teased about it. Tsundere (though she rarely shows the "dere" side). Height: 144cm, Weight: 36kg, B71-W53-H77 (A-cup). Her in-game class is Priest. She is the cornerstone of the party, handling healing as well as support skills. She has slightly padded her avatar's chest size.

[Nepgear] The Goddess Candidate of Planeptune and Neptune's younger sister. She is reliable and often mistaken for the older sister based on appearance, but she loves her sister dearly and is very soft on Neptune. She is actually a mechanical otaku with a strong grasp of machinery and networking. Since the world is fantasy this time, she is worried her individuality might be lost. She admires her sister Neptune and often praises her with "As expected of Big Sis!" She is close friends with Uni. Height: 154cm, Weight: 40kg, B78-W56-H80 (C-cup). Her in-game class is Magician. A long-range type who leaves large openings but fires devastating magic from a distance. [Uni] The Goddess Candidate of Lastation and Noire's younger sister. A little-devil type tsundere girl, but polite toward her superiors. Contrary to her appearance, she is a hardcore military otaku who loves guns. She is very close with the machine-loving Nepgear, and they go parts-hunting together on holidays. Height: 149cm, Weight: 39kg, B77-W55-H81 (B-cup). Her in-game class is Thief. She uses dual pistols and martial arts in speedy combat to toy with enemies. Her outfit is quite revealing. [Rom] The Goddess Candidate of Lowee and Blanc's younger sister. She is twins with Ram, and Rom is the older one. She has a shy and timid personality and is somewhat wary of strangers. She can't speak her mind clearly like Ram, so she has a habit of vocalizing her feelings through onomatopoeia instead. She had a hard time creating her "4 Goddesses Online" account because the kanji were difficult. She calls Ram "Ram-chan." Height: 132cm, Weight: 28kg, B: A little bit there, W: Thin, H: Slightly (AA-cup). Her in-game class is Samurai. Every attack is fast, and she is unrivaled in close combat, but she is difficult to handle and meant for advanced players. [Ram] The Goddess Candidate of Lowee and Blanc's younger sister. She is twins with Ram, and Ram is the younger one. An active and mischievous personality who always leads the shy Rom around. She usually plays pranks on everyone regardless of who they are, but she is keeping her promise to Blanc not to do so inside the online game. The kanji were difficult, but she managed to create her "4 Goddesses Online" account by intuition. She calls Rom "Rom-chan." Height: 132cm, Weight: 27kg, B: A little bit there, W: Thin, H: Slightly (AA-cup). Her in-game class is Ninja. A mid-range type who uses ninjutsu and martial arts to quickly break enemies. She apparently fights with a "hit and away" tactic.

An NPC. Vert fell in love with her at first sight and designated her as a sister candidate. She speaks in a polite, formal manner.

A player.

A player.

One of the Demon King's executives known as the Twin Walls. [Dark Knight] [Minotaur]

The final boss of this game. He is currently attempting to break a 1,000-year seal.