Diana (ダイアナ, Daiana) is the Future daughter of Luna and Artemis. She first appears when the Sailor Soldiers travel to the 30th century in the Black Moon arc. After defeating Death Phantom, the Sailor Soldiers return to the 20th century and Diana joins them. In the anime only, she appears until Sailor Moon SuperS, calling Artemis her father, to Luna's initial dismay. Only later it is revealed that Diana has come from the Future and that her mother is Luna. Just as Luna and Artemis guide Usagi and Minako, Diana acts as a guardian to Chibiusa. She is very curious, eager to help, and deeply polite, always addressing Usagi and Mamoru with the Japanese honorific "-sama" and calling Chibiusa by her formal title, Small Lady. She is able to help the Sailor Soldiers on occasion, despite her youth, and often because of the knowledge she had gained in the Future.

The function of the Sailor Soldiers themselves has been analyzed by critics, often in terms of feminist theory. Susan J. Napier described the Sailor Soldiers as "powerful, yet childlike", and suggested that this is because Sailor Moon is aimed towards an audience of young girls. She stated that the Sailor Soldiers readily accept their powers and destinies and do not agonize over them, which can be read as an expression of power and success. The Sailor Soldiers have been described as merging male and female traits, being both desirable and powerful. As sexualized teen heroines, they are significantly different from the sexless representation of 1980s teen heroines such as Nausicaä. Anne Allison noted that the use of the Sailor fuku as a costume makes it easy for girls to identify with the Sailor Soldiers, but also for older males to see them as sex symbols. Unlike the female Power Rangers, who as the series go on become more unisex in both costume and poses, the Sailor Soldiers' costumes become frillier and more "feminine".

Differences in character between the Sailor Soldiers mirror differences in their hairstyles, fashion, and magical items, which has translated well into doll lines. Sales of the Sailor Soldiers fashion dolls overtook those of Licca-chan in the 1990s. Mattel attributed this to the "fashion-action" blend of the Sailor Moon storyline; doll accessories included both fashion items and the Soldier's weapons. The first line of dolls included Queen Beryl, the first major antagonist of the series, a decision that was described as a "radical idea". The first dolls based on Chibiusa surprised Takeuchi because, at that time, the author had not even finalized the character's hairstyle, and explains that viewing the doll's head from various angles was wonderful. Bandai introduced a line of little dolls that included the Amazoness Quartet and, according to Takeuchi, these were their favorite because "with their costumes and faithfulness to the originals, the dolls really excelled." Bandai has released several S.H. Figuarts based on the characters' appearances from both the first anime adaptation and Sailor Moon Crystal. Among those figures are the Sailor Soldiers, Tuxedo Mask, Black Lady, and Zoisite disguised as Sailor Moon. In early 2014, Megahouse released a set of trading figures consisting of twelve figurines, two for each Sailor Soldier and two for Tuxedo Mask.

Several characters, including Sailor Soldiers, villains, supporting characters, and monsters of the day are featured in a collectible card game which was released in 2000 by Dart Flipcards. A collaboration between Sailor Moon and Capcom took place in March 2018 as part of the 25th anniversary celebration of the Sailor Moon franchise. In this collaboration, the Felyne cat companion resembles Luna and wields Usagi's Cutie Moon Rod weapon in the Monster Hunter XX expansion of Monster Hunter Generations.

In the Japanese series, Haruna was originally voiced by Chiyoko Kawashima in Sailor Moon until her retirement in 2001. Akemi Kanda voices her from Crystal onwards. In the DIC English adaptation, she is voiced by Nadine Rabinovitch. In the Viz Media English adaptation, her voice is supplied by Julie Ann Taylor. She is played by Tomoko Otakara in the live-action series. In the musicals, Haruna is portrayed at various points by Kasumi Hyuuga and Kiho Seishi.

Sailor Cosmos (セーラーコスモス, Sērā Kosumosu) is the ultimate form of Sailor Moon. She comes from a Future which has been destroyed by the battle with Sailor Chaos; after ages of fighting, she despairs and flees to the past as the infant Chibichibi, to encourage Eternal Sailor Moon to defeat Chaos in the final battle of the series. At first, she wants Sailor Moon to destroy the Galaxy Cauldron altogether, ensuring Chaos' destruction, but Sailor Moon protests, realizing that if the Cauldron is destroyed no more stars will be born, leaving the Galaxy without a Future. She chooses to sacrifice herself to the Cauldron and seal Chaos away, which Cosmos finally realizes to have been the right decision. Reminded of the strength and courage she herself needs to have, she returns to the Future with new hope. After the end of the anime adaptation, Takeuchi commented that she wished Sailor Cosmos had been used in Sailor Moon Sailor Stars. In the musicals, Sailor Cosmos is played by Satomi Okubo, who plays Usagi Tsukino/Sailor Moon between 2013 and 2015.

In the original Japanese series, Ikuko is voiced by Sanae Takagi in the first anime and by Yuko Mizutani in Crystal until her death in 2016. In the DIC and Cloverway English dubs, she is voiced by Barbara Radecki. In the Viz Media English dub, her voice is supplied by Tara Platt. Kaori Moriwaka portrays Ikuko in the live-action series.