During the Silver Millennium of the Solar System, other stars were flourishing elsewhere, some in different galaxies entirely. One such star was Mannen ( マンネン星, Mannensei ), a planet outside the Milky Way notable for its exuberant natural beauty. Though Mannen was divided into several factions at odds with one another, they did have a leader, the Princess Kiyomi of the Omoto Dynasty. Despite her title, Kiyomi was not simply royalty. She was the planet’s one and only Great Priestess: The bearer of the Sacred Jewel, a holy artifact with legendary power that had been passed down from one royal woman to another since before living memory, ever since the days of the first Great Priestess, Midoriko.
In truth, the Sacred Jewel was Kiyomi’s Sailor Crystal. In addition to being a spiritual leader, she had been chosen by the planet itself as its destined protector, Sailor Mannen. It was her duty to keep her home and her people safe from harm — not just from external dangers, but from the threat of yōkai as well. These beings roamed the planet, more often than not doing as they pleased and harming the Mannensian people, so that there was an unbreachable divide between both races. In spite of this, and in spite of her devotion to her duty, Kiyomi could not help falling in love with the hanyō Inuyasha. While their love blossomed, a thief by the name Onigumo watched from the shadows, desiring both Kiyomi and her Jewel; however, he was severely hurt and could not move, so that he sold his soul to hungry yōkai in exchange for the power he needed.
In the meantime, Kiyomi had come to realize that her love wasn’t hopeless: Though she could not cease to be the planet’s protector, she could use the Jewel to make her beloved human and live with him. However, the day of their promised meeting was also the day that the wretched Naraku was born from the fusion of Onigumo’s evil heart and a hundred yōkai. He pitted the lovers against each other in an elaborate scheme, and in the end Kiyomi pinned Inuyasha to the Tree of Ages with an arrow to the chest, perishing from her wounds afterward.
As she lay dying, the princess found herself wishing for another chance: I want to meet Inuyasha again, as an ordinary woman. The strength and sincerity of her wish interfered with the laws of life, and so she gained an ordinary Star Seed rather than a Sailor Crystal. In her next life, she would be simply a normal woman with no memory of her previous incarnation, and she would be destined to find her beloved again. However, Sailor Mannen’s Crystal could not simply cease to exist, as that would leave the planet defenseless, and Kiyomi’s wish had the unprecedented effect of her memories being retained by the Crystal, rather than it beginning a new life cycle. She wanted to meet Inuyasha as an ordinary woman, but she also wanted to be herself still, and both could not happen at once — so that she effectively split her soul in two.
Both Star Seed and Sailor Crystal were sent centuries into the future, to the planet Earth, where they were born in the country of Japan as Higurashi Kagome and Akatsuki Kikyō, respectively. The former was a perfectly normal girl, while the latter was a Sailor Senshi plagued with strange dreams and exhibiting psychic powers from a young age; Kikyō awakened fully at the age of fifteen, and thereafter she stepped into the role of one of Tokyo’s many protectors. However, while the Solar System Senshi fought several enemies, she had only one great foe: Naraku had reincarnated in this day and age as well, and he had several denizens working under him. The first was Kanna, the void, but more and more followed. Also unlike the Sol System guardians, Sailor Mannen was all alone... or, not quite. Throughout her battles with Naraku, she kept crossing paths with her “other self”, Higurashi Kagome, and with her fated lover Inuyasha. A very complex relationship developed between the trio, with both Kagome and Kikyō loving Inuyasha just like Kiyomi had, and Inuyasha loving both as well, each in a different way.
In the end, Sailor Mannen managed to defeat Naraku, as she should have done in her past life. She also prevailed over Magatsuhi, the embodiment of an immense evil and chaos ( perhaps even worse than Naraku ) that was drawn to the Sacred Jewel’s light. She managed to do so in part thanks to her own power, in part thanks to Inuyasha ( who had also retained some of his past life’s powers, and all his memories ) being with her and lending her his strength. Fighting side by side and seeing each other at their weakest points, they came to the realization that they had been reborn to meet each other again. In the aftermath of the wars against Naraku and Magatsuhi, they made the decision to return to Mannen together, while Kagome chose to live out her life on Earth; despite the complicated emotions that had strained their relationship for so long, the three of them had become friends first and foremost.
Upon returning to their home planet, Kikyō and Inuyasha found that it was much changed from what they remembered of centuries prior. Losing their dear protector, their sole reason to be united at all, had caused the internal wars to gradually worsen, and after hundreds of years the planet was practically devastated. Thanks to the immense purifying and healing power of the Sacred Jewel, however, the planet was restored to its former glory. The Mannensian peoples, who had thought their Sailor Senshi forever lost, were overjoyed to have her back. Negotiations for peace commenced as well, and though hard they were mostly successful.
After the peace was mostly established Kikyō ascended the throne not as Princess, but as Empress, with Inuyasha as her consort and Emperor. In spite of their titles, she is not the sole ruler of the planet; she is more a diplomat than anything, and each province has its own head and its own rules, but the deep-running respect ( worship, if you will ) of the Mannensian people for their Sailor Senshi and Great Priestess led to her practically being bestowed with the title rather than claiming it. As Mannen’s Empress, she expanded their interplanetary relations, becoming allied to Kinmoku and to her birth planet, which was then governed by Neo Queen Serenity.
I have a post about Mannen in the planning stages, and I’ll link it here when it’s done. It’ll cover such topics as culture, society, locations, cuisine...
The name Mannen is a pun with several layers. Mannensei ( or Omoto, hence Kiyomi’s dynasty ) is an evergreen plant native to China, Korea and Japan. It’s a widely beloved plant in Japan, which ties in with how Kikyō is so beloved in her canon, and so rooted to her culture; the leaves are green and the berries are red, which covers both Kagome and Kikyō’s theme colors. The Mannensei is also thought to represent good fortune, and it’s known in English as sacred lily. Sacred is quite obvious, and the lily is often associated with purity. However, the suffix -sei also means ‘planet’, so in Japanese we have both Mannensei (the plant) and Mannensei (the planet).
As for Kiyomi, Kiyo is a feminine name that was used at least from the 1100s to the 1600s. It can also serve as a prefix, since Kiyoko was a Japanese empress. ‘Kiyo’ means purity or holiness, and mi can be either an alternate reading of -ko (child) or the ‘mi’ of beauty, depending on kanji. Thus: Child of purity / holiness, or beautiful purity / holiness. It’s a name that fits both Kikyō and Kagome, in my opinion.
Kikyō attended the same public school as Usagi and most of the Inner Senshi sans Rei. Yes, I know, Kikyō is totally the type that would fit right into T.A, but she’s also an orphan and the government wouldn’t pay for a private school.
Speaking of which, Kaede did go to Mannen with her and Inuyasha, I just didn’t get around to mentioning it. The Mannensians also have very long lifespans naturally, and the three of them also do despite being born on Earth, because I say so they’re under the influence of the Sacred Jewel.