— Words of the Seidan Guard about the realm of Seido.
The Seidan Guard or the Seidan Guardsmen is an ancient and current military organization and militant police force that protects the highly advanced civilization of Seido and strictly responsible for everything that goes on within that seemingly perfect world. Hotaru is in charge of this local law enforcement as their supreme commander and favorite soldier while because of his chivalry, zealotry, and love for order, is being hailed as Seido's hero.
The Seidan Guards like their fellow Seidan citizens, are humanoid in form but, like many other species in the realms of Mortal Kombat, they also possess greater affinities with magic and have a much longer life expectancy. And like their people's lifestyle, their obsession with structure, organization and even perfection has led to the fact that they seem to care more about such abstract things than they do about life and death, which makes them, curiously, a lot like the Chaosrealmers from the Realm of Chaos, the opposite of the Realm of Order. Despite the egalitarian, clear outlook of their society, Seidans are tense people and many have reservations about their ruling caste, as is demonstrated by the Seidan Resistance movement led by Darrius. Many inhabitants are also well-adapted to the nature of their homeworld, as they often appear busy and/or rushing to their destinations. Despite the strict laws unlike the Seidan Guard, some everyday citizens (excluding the Seidan Resistance and the former Seidan Guardsman Dairou) still commit serious crimes such as murder, though they never get away with their crimes.