The Four Gods are based on four mythological creatures from Chinese mythology. They appear in The Last Blade with their Japanese associated names. While The Last Blade specifically refers to four main gods, it also uses a fifth figure like the Wu Xing and other systems, and this figure has historically been either a mediator or a unique fifth element. The five and their associations are as follows:
- Seiryū - a blue dragon (East, Spring, Wood)
- Benevolent and powerful ruler of the east. In Japan, it's said to drink from the waterfall within Kiyomizu Temple at nighttime.
- Suzaku - a vermilion bird (South, Summer, Fire)
- A majestic bird with a noble behavior that's picky about what it eats and where it perches.
- Byakko - a white tiger (West, Autumn, Metal)
- Tigers were considered to be the king of all beasts in China, and white tigers were mythic elder versions of tigers. A white tiger is said to only appear when the world is at peace or if the Emperor ruled with virtue.
- Genbu - a black tortoise entwined with a snake (North, Winter, Water)
- The tortoise and the snake were symbols of longevity in China and were symbols of honor with a similar meaning in Japan. The word "tortoise" could also mean "taboo" in Chinese.
- Kouryu - the yellow dragon (Center, between-seasons, Earth)
- The yellow dragon is also traditionally a representation of the Emperor of China, who is revered as a deity in his own right; this figure is considered to be the child of the gods. This is also why emperors of China are often associated with dragons and the color yellow.
In the Last Blade universe, the specific four gods possess people worthy of their powers. Each user exhibits their select god's powers to a different degree of efficiency. The gods also have the duty of protecting the seal over "Hell's Portal", a split world separated from this one before the time of man. Suzaku, offended by the people's indifference to their existence with the growing acceptance of European ideals, breaks his responsibilities and opens the gate. The deity is wielded by Shinnosuke Kagami.
His act of defiance awakens the other gods in their respective owners. Shigen Naoe went berserk from his deity, Byakko, unused to the sheer power of it. Like Shinnosuke, Genbu no Okina had been aware of his god's powers before the opening of Hell's Portal, Genbu being the reason for his lengthy lifespan. The youngest wielder, Kaede, was reluctant to use his god's powers (Seiryū) as he was afraid of losing himself to the god. While Okina calmed Shigen down and brought him back to his senses, Kaede rushed off to stop Shinnosuke's plans of using Hell's Portal for himself. Kaede defeats him but the portal was opened far too long, leaving the gods unable to reseal it.
In order to close the gate again, the Sealing Maiden must be found to perform a ritual with the Four Gods and seal it. The character chosen to take the role of the Sealing Maiden was Yuki, though the true identity of the Maiden is kept a secret from Kaede. Each avatar worked individually to protect the Maiden from the hazards that came out of Hell's Portal. The main dangers to her are "The Yellow Dragon", who possessed the spirit of Gaisei, and "The Messenger from Afar", a being given birth from the first death in the world. At the series's climax, she succeeds in her mission, taking the rogue souls from Hell's Portal with her. Unfortunately for Kaede, this meant he would never see Yuki again, something he slowly accepted later on.
The fates of the four gods are seen through their respective character endings. Shigen dies performing his duties, with his daughter Kotetsu inheriting Byakko's mantle. Shinnosuke's faith in humanity returns, becoming somewhat a father figure to Kotetsu. Kaede gets used to being Seiryu, and Okina ponders about the battle and Hell's gate, and his own longetivity.