Irin (天神族, Irin), also referred to as Angels, are spirits who guide the souls of the dead and protect the souls of the living.
Irin are charged with executing Ten'i, or Divine Will. They are servants of Ten'i, sacrificing everything for the duty of protecting the universe. This includes maintaining order throughout the realms by protecting the residents of each dimension.
The highest Celestial law states that "the individual must be sacrificed for the many." This means that, although Irin are charged with protecting humans, the balance of the universe is of infinitely greater importance than any life, and to maintain the balance of the forces, they must kill humans as necessary and ferrying the departed souls to the next world. Thus, Irin must make a decision regarding each life: for each life they save, they must take another. Irin generally do not kill humans in most circumstances. Following the person's death, they ferry their soul to the afterlife.
Thousands of years ago, a war broke out between different factions of the Irin. The rebelling angels, which called themselves Legion, fought against the Irin. They lost and were cast down to Yomi, a dimension below that of the physical realm, where they remain to this day.
Celestials may take many forms, but generally remain Ethereal even when in the Physical Realm. Occasionally they will take Corporeal form to reveal themselves to a human.
They may take the form of any living or nonliving thing. In their true form they usually have horns, pointed ears, slit pupils, and wings. Most Irin are quite tall; it is stated that Isasu, standing at 6'1", is very short for his race.
Irin wear robes in accordance with their rank. The standard wear is a long-sleeved white kimono with white hakama and a long obi that extends down the front of the hakama. Robe colors are frequently incorporate white, blue, and gold into their designs. Red and white are also common.
There are several known classes, or ranks, of Irin. These ranks are divided into three spheres:
First Tier: This tier governs the heavenly realms and serves as the governing council above all others. Unlike the lower tiers, they don masks and wear especially ornamental uniforms.
- Seraphim (Serafu) - The most powerful rank of an Irin. They are the leaders of all angels. There are only twelve of them, one from each tribe, and together they make up the Council of the Stars. Their law is absolute. They are highly respected and feared by all others, even the Cherubim directly under them.
- Cherubim (Kerubu)- The second rank beneath Seraphim. They are the guardians and gatekeepers of the Celestial plane.
- Ophanim (Ofanimu) - They are the gatekeepers of the Celestial Plane. They are closely affiliated to, although subordinate to, the Cherubim.
- Hashmallim - They regulate the duties of lower angels. They are rarely seen
- Erelim (singular, Er'el) - They are a warrior class of angel.
- Archangels (also referred to as Demigods)
- Malakim (often simply referred to as Angels) - Malakim are the lowest rank and also the most common. They are responsible for most of the tasks relating to the human world.
Depending on the rank, angels have different duties. Usually the protection of humans is delegated to lower-class Irin; those of the upper echelons of Irin society do not involve themselves in human affairs. This explains why Madoka, Gen'ya, and later Isasu appear clueless about many things human.
They typically reside in Takama but often make journeys to the world of the living by passing through the Ukihashi.
Irin are servants of Ten'i, and as such hold this duty as greater importance than anything else. Irin that sacrifice Ten'i to save human lives, for selfish purposes, or for personal gain may be considered in rebellion, and therefore a danger to the order of the universe. Irin that break the Law of Ten'i are cast down to the human world as Ochigami to suffer and pay for their sins.
All Irin use abilities based on their Hakuriki, or life force, as well as the life force of the universe. They possess both the power to use their Hakuriki as well as innate abilities that are based on their intransient state, such as shapeshifting, healing, strength, and speed. They may open Portals to other dimensions as well as manipulate spiritual energy around them.
- Speed (瞬動)
- Teleport/Apportation (瞬送)
- Regeneration (再生)
- Summoning a Godsword (神刀・神燈)
Irin are immortal, but depend on energy around them to survive. They cannot exist peacably in the Physical Realm for extended amounts of time.
Irin in the Spirit World are immortal. They live indefinitely and through age grow more adept at manipulating their power. When they feel they have aged long enough, they may choose to return themselves back to the earth.
Irin who have fallen to the Mortal World become mortals themselves.  through being disconnected with the source of their vitality. Ochigami make up for this by draining the vitality of other creatures, mostly humans.
"Irin" generally refers to those spiritual beings who dwell in Takama. While Ochigami and Legion consists of individuals who were once residents of Takama, they are no longer considered Celestials but Earth-Dwellers.