HiME , also known as Valkyries and Ikusahimes , is a name that stands for " Hi ghly-Advanced M aterializing E quipment" and refers to women with the ability to materialize solid objects from photons . HiME can be identified by an identical birthmark they all possess somewhere on their body. In addition, only HiME can see a special red star ( Hime-boshi ) in the sky near the Moon . HiME is a backronym of Hime , which is Japanese for princess.

PRINCESS (Manga only) An ability similar to that of the HiME, developed by the Searrs Group scientists. It stands for P erfect r ealization of in dependent ac cess . These individuals can summon a Child without the presence of a Key.

Elements are weapons created by focusing a HiME's ability to create solid matter from photons. They serve as proof that a HiME has become aware of their own power. Elements usually take the form of some sort of Close Combat weapon(although there are exceptions.).

Child is the name of the powerful beings who choose to act as guardians for the HiME. They appear to be robotic in nature, but they are sentient and intelligent beings. In exchange for accepting the protection of a Child, that HiME must put her most important person (known in the manga as a 'Key') on the line. That means, the person the HiME cares about the most has his or her life-force bonded to that of the Child. If the Child dies, so does that person and the Hime loses the ability to summon their Child. An exception is if the Hime changes their most important person; though only two Himes in the anime did this. Also, the stronger the bond between the HiME and the person, the stronger the Child becomes(i.e it gets bigger).

Orphan is the name of the monsters that the Himes fight early in the series. As explained in one of the show's DVD specials, Orphans are the same as Childs. The only difference is that Orphans do not attach themselves to a person. A Child is able to "resonate" with a Hime's soul, creating the bond. Orphans attack people because they are attracted to the idea of such resonance, but lack the capability. There is a visual difference to Childs and Orphans, where the former is robotic in appearance, the latter is organic and more resembles a cross from a mystical creature and a warped version of a real animal(where as Childs resemble one creature quite clearly). Some Orphans have the capability to separate into smaller creatures(such as the one that steals lingerie and the spider-esque Orphan that attacked Takumi) and regenerate(such as the monk-like Orphan during the wedding) lost body parts.

Key A person who is affiliated with a HiME. The presence of a Key is required in order for them to summon their Child. HiME can have multiple Keys, share Keys or even be Keys with each other. The concept of Keys is only present in the manga. In the anime, they are simply referred to as a Hime's "most important person," and unlike the manga, their physical presence is not required to summon a Child. In the Anime, all HiMEs thought the "most important person" Nagi was referring to was themselves, Akane found out the hard way that this was not what Nagi meant. Also, if two HiMEs are each other's Key, it would make it impossible for either one to win, as the destruction of one Child would cause the other HiME to perish, killing her child and making the attacker perish as well.

Otome is a job for girls and womans with special powers, for this one, materialising a robe. Nanomachine is injected in order to become an otome. It;s the lastes technology. But the most important thing is that Otome menas Maiden, so if an Otome has an intimate relationship with a man, her power will be gone because of the spermatozoid destroying the nanomachine.

HiME Star is a legend. It is said, when the HiME star is glowing red, Otomes will be freed from their chains of fate. I mean, for example, materializing a robe without command from their master.

Elements are weapons created by focusing a Otome's nano ability to create solid matter from nano photons.

Five Pillars/Five Columns are special Otomes who serve no master save for Garderrobe and Fumi, the first Otome. These five are considered among the strongest of all Otome in the world. They are, in order: Sara, Natsuki, Shizuru, Nao, and Maya. Mai was planned to be the fourth before her missing. So Nao is chosen.

Twelve Kingdoms War is a war years ago between the twelve kingdoms, and of course between their Otomes. Fumi Himeno is said to end up this war.

GEM (Generable Enigmatic Matrix) is a technology of nanomachine which can make a person materialise a robe to maintain the power of Otome.

REM (Reinforcing Enigmatic Matrix) is another variant of GEM, a person can maintain the power of Otome within 300 seconds only. Midori and Aswads use this technology to support their illness.