In the world of Daikuuriku, all children are born female; but once they become a young adult, they may choose which sex they will become. In this world which is at war with itself, the women of Simalacrum find themselves charged with the task of piloting the ancient machines known as Simoun in hopes of turning the tide of war. Though originally simple ceremonial machines, the most gifted of pilots can turn the glowing "ri maajon" of their rituals onto their enemies and obliterate them from the skies using these Simoun. However, it takes a special bond between two highly gifted girls to successfully pilot a Simoun. With the toll of blood and pain that these previously innocent girls are taking, how many will be able to carry on, even knowing that they are the only real thing standing between freedom and subjugation of their land?
MKR is a Clamp anime about three girls who are taken from Tokyo during a school field trip, and transported into a fantasy world. Hikaru Shidou, Umi Ryuzaaki, and Fuu Hououji must fight a slew of enemies, overcome trials and tribulations, and face their inner demons to save Cephiro, a wonderfully detailed world, from a dastardly evil and powerful Priest, Zagato.
Giant mechas in fantasy worlds and girls wearing pauldrons are two of the main similarities between Simoun and Magic Knight Rayearth. Besides the obvious, though, both sets of characters are on a mission for powers beyond themselves, only to begin to question their journey later on.
Arika Yumemiya is a poor yet energetic girl who has come to the city to become an Otome – a female warrior with the power to match an entire army. She quickly befriends her irritable fellow student Nina Wong and Princess Mashiro, the queen-to-be. With the help of her mysterious benefactor and abundant natural talent, she’s able to overcome the trials of everyday life in the competitive Garderobe Academy, but darker schemes are afoot. How will her new friendships fare, when secrets of the past and present are brought forth to spark a fight for the crown, and more?
Mai Otome and Simoun both feature a similarly clueless, light-hearted protagonist set amidst a backdrop of various houses vying for power and the protagonists being somewhat of a key to this power. The themes and the bubbly colourful animation style prevalent in both will ensure that if you liked one you will like the other.
Guided by a star only they can see, a group of maidens known as HiMEs have begun to gather at Fuuka Academy. These young women have been endowed with dangerous supernatural powers that they can use to their heart's content, but there's a price: to wield them, they must put their most important thing on the line. Now, in the midst of school work and friendships, they find themselves caught in the midst of strange conspiracies seemingly related to the terrifying monsters that attack them. Is the power of the HiMEs strong enough to save themselves and the ones they love?
I believe that his is one of the easiest rec I ever made, those two shows are strikingly similar in a ton of ways. Both shows are pretty slow to start, they spend a LOT of time to properly introduce every character (and there are plenty in both My-HiME and Simoun). Shoujo-ai is probably THE main theme of Simoun, and while it's not as much predominant in My-Hime, you will also find hints of yuri in it. If you enjoy shows that are surprisingly tragic like My-HiME or Simoun, or you simply have a thing for shoujo-ai stories, make sure you watch both series!
Centuries ago, humanity carelessly ravaged the Earth’s environment, forcing them to leave and form a colony elsewhere. To prevent the same mistakes from happening again, they allow a supercomputer to run their lives. Children are genetically engineered and at the age of fourteen take ‘adulthood exams’, a process whereby the supercomputer ensures they are suitable for membership in this perfect society. Those who pass have their memories erased and are guided into the next stage of their life; those who fail are immediately destroyed. Jomy is a boy about to take his adulthood exams, but things go terribly wrong when a man wreathed in light interrupts the process. He is a Mu -- an aberration, a new generation of human with extraordinary powers usually detected and eliminated by the supercomputer. This man tells Jomy he too is a Mu and introduces him to the Mu society. They are a rebel group in hiding from the oppressive human regime, who live in the hope that they will find a life of peace on Earth some day. Can Jomy leave behind all that he has known, come to terms with his awakening powers, and help the Mu return to their beloved Terra?
Both shows follow a beautifully constructed cast of characters, going through much trial and hardship in their respective worlds. A great musical score is also present in both series, as is a gripping storyline set in an environment with sci-fi elements.
The deep relationships between the characters is another aspect which these two great shows share, both putting emphasis on character growth and not shying away from same-gender relationships.