Quasi-Spirits (準精霊, Jun Seirei?) are beings that live in the Neighboring World after the Spirits left for the real world. Unlike a normal Spirit, they only possess a fragment of a Sephira Crystal. They make up the majority of the cast of Date A Live Fragment: Date A Bullet.
While living in the Neighboring World, a Quasi-Spirits' existence is powered by their Sephira fragment. If that crystal is damaged or removed, the Quasi-Spirit in question will immediately begin to fade away. The body of a Quasi-Spirit is actually formed of Reiryoku by the image acknowledged by their Sephira, including the physical injuries it sustained. If the Sephira believes that it has died, the Quasi-Spirit would die regardless of if they are already healed.
In some cases, this can result in impossible physiological traits, such as Rinemu who doesn't sweat even after long walk because she believes "Idols don't sweat and don't need to go to toilet", but sweats profusely when she realized her career as idol had ended. Another instance of this was when Rinemu's bust size changed extremely due to her belief in the myth that drinking milk can make one's breasts grow larger.
Additionally, the vast majority of Quasi-Spirits have portions of their memories of their old lives as humans in the other world. However, the majority can't remember how they ended up lost in the Neighboring World to begin with. It is also not uncommon for a Quasi-Spirit to completely lose their memories and even their entire personality during their stay in the Neighboring World. Despite losing their memories though, Quasi-Spirits have knowledge about the real world. They also know they are Quasi-Spirit and their own abilities, such as Astral Dress and Unsigned Angels.
While living in the Neighboring World, the physical body is inconsequential compared to the real world due to the laws of the Neighboring World being completely different. What is essential for their survival is having a dream or aspirations for the future. A Quasi-Spirit that isn't attached to a strong desire will eventually completely fade away regardless of the condition of their Sephira fragment.
In the Neighboring World, a Quasi-Spirit has territory. This territory acts as their protection. Inside this Territory, a Quasi-Spirit can realize anything they want; although there are limitations. Such as that a Quasi-Spirit can only create things that suit the area they are in, and providing adequate power for creation. The ability to create this territory could also be linked to ability to realize their Angel and Astral Dress and thus makes them a full-fledged Quasi-Spirit, not a mere newborn Empty.
A Quasi-Spirit can consume the Sephira fragment of other Quasi-Spirits to gain power. This is most often practiced in Malkuth, but other regions usually have aversion against such an act of cannibalism.
Empty (エンプティ, Enputi?) is a state a Quasi-Spirit enters after losing the will to live. There are many girls who became Empty after falling into the Neighboring World because they lose all their memories, identity, and purpose as soon as they arrive.
Empty are physically characterized by their white coloration, from hair to Astral Dress. Their energy is weak and, if left alone, they will disintegrate into light particles, which is commonly termed as "Lost."
Psychologically, becoming Empty is a horrifying experience, as they can feel their sense of self fade away. It comes in form of lethargy and abandonment of everything in the world. According to Hibiki, who once had fell into a near terminal stage, Empty would even grow detached from their fear of death. There is discourse among Quasi-Spirits regarding the transformation into an Empty. Some believe becoming Empty rids a Quasi-Spirit of their suffering and pain while everything disappears. Retsumi Jugasaki mentioned that becoming Empty was like a disease that destroys desire to leave and decays the sufferer, and found it more painful an experience than Hibiki did as she didn't fall into such a serious stage. Despite this, Empty can still think. Their acceptance of death also allows them to fight without any restraint, abandoning taboos such as using their Unsigned Angels on others.
Empty are commonly considered as insignificant. In regions where society develops, they are often used for menial work such as servants or even slaves because of their obedient nature. The Empty under the White Queen are fanatical followers who would gladly sacrifice themselves for their beloved queen.
Unsigned Angels (無銘天使, Mumei Tenshi?) are the personalized weapons of each individual Quasi-Spirit. While the appearance of each weapon might widely vary, the abilities usually revolve around the attribute of the Quasi-Spirits' genus. While similar to the Angels employed by the Spirits, an Unsigned Angel lacks the sheer authority and might possessed by a genuine Angel.
As of result of Unsigned Angels being comprised of Reiryoku, Quasi-Spirits can freely summon or dismiss their Unsigned Angel at will depending on how much Reiryoku they have left. According to Hibiki, an Unsigned Angel matches their respective Quasi-Spirit just like genetic fingerprints. While other people may pick up and use another Quasi-Spirit's Unsigned Angel as a weapon, only the true wielder can activate its full powers. Despite this, there are people like the White Queen, who are known to have armories storing Unsigned Angels stolen from other Quasi-Spirits.
Each Quasi-Spirit has a genus that is determined by the type of their fragment out of the ten Sephira Crystals. Their genus determines a rough archetype of their powers.
- First genus (光): Light
- Second genus (情報): Information
- Third genus (影): Shadow
- Fourth genus (氷): Ice
- Fifth genus (炎): Fire
- Sixth genus (封印): Sealing
- Seventh genus (変化 ): Transformation
- Eighth genus (風): Wind
- Ninth genus (音): Sound
- Tenth genus (物質): Substance/Material
According to Sheri, types 1, 4, 5, 8, 9, 10 account for 80% of all Quasi Spirits. The other types are viewed as uncommon, with Type 3 being extremely rare at below 1%.
The criteria to become a Dominion varies between regions. Chokmah was stated to rely on tradition; only Quasi-Spirits who meet the requirements can become Dominion. In Malkuth, strength and power is favored, with the strongest becoming Dominion, and in Yesod, Dominions are decided by popular vote.
Due to their ruling over their respective territories with an iron-fist, Hibiki has noted that traveling in-between regions has now become much more difficult than it has before in the past.
Dominions of each region:
- Keter: Unknown
- Chokmah: Maya Yukishiro
- Binah: White Queen
- Ex-Dominion: Carte À Jouer
- Chesed: Ariadne Foxlot
- Gevurah: Haraka Kagarike
- Tiphereth: Oka Miyafuji
- Netzach: Yuri Sagakure
- Hod: Retsumi Jugasaki
- Ex-Dominion: Kareha Banouin
- Yesod: Mizuha Banouin and Rinemu Kirari
- Malkuth: Currently None
- Ex-Dominion: Doll Master
- Hibiki Higoromo
- Inui Yume
- Yue Hiryu
- Doll Master
- Aiai Nogi
- Yui Sagakure
- Ayame Takeshita
- Isami Hijikata
- Sheri Musika
- Furue Tonami
- Rinemu Kirari
- Mayuka Momozono
- Mizuha Banouin
- Maya Yukishiro
- Ariadne Foxlot
- Haraka Kagarike
- Oka Miyafuji
- Yuri Sagakure
- Kareha Banouin
- Carte À Jouer
- In the afterword of the first volume of Date A Bullet, Yūichirō Higashide described the Quasi-Spirits as girls who have gotten lost in the Neighboring World.