The Four Houses (also known as Clans) are a group of rival factions in the Dragon Kingdom of Mobius. Each clan is limited to one particular species of Mobian, each being led by its own Bride, who is considered as being "married" to the house above anything. There were four clans in total, each battling during the Clan Wars. In 3237, the leader of the Yagyu Clan was slain by Jun Kun after refusing a bribe to join the Iron Dominion. Her death was credited to Regina Ferrum so that she took over the Yagyu Clan. Following this, Regina spread rumours to each of the clans that the other ones had joined the Iron Dominion, and used the Yagyu to randomly support the clans in various battles between them, thus convincing them this was true. Subsequently, the three remaining brides, fearing their clans would be overrun, swore allegiance to the Iron Dominion. However, due to a variety of reasons, each clan was eventually convinced to break ties to the Dominion, leaving it far less powerful. (StH: #201, #207, #211, CSE)
- Yagyu Clan (formerly led by the Bride of Rich Nights, currently led by Yagyu Lords) — a clan of bats once renowned as swordsmen before reduced to mere thieves
- Shinobi Clan (led by Bride of Constant Vigil) — a clan of chameleons who act as spies and informants
- Raiju Clan (led by Bride of Conquering Storm) — a clan of lynxes known for aggression, now part of the Dragon Kingdom Dark Egg Legion
- Gossamer Clan (led by Bride of the Endless Reach) — a clan of spiders who work with prophecy
- The banner of each Clan symbolizes the name of each Bride that leads them.
- The Four Houses are not the only Mobian groups to be named as clans; others include the Knuckles Clan and the Nocturnus Clan.
- With the exception of the Yagyu Clan, each of the Four Houses has had a member or members introduced outside the Clan, as well as by an individual name rather than a title: