The shikigami in Yami no Matsuei are guardian spirits; creatures which can be summoned by shinigami. When in battle in the living world, shikigami appear as various types of mythological creatures. There are different kinds of shikigami, roughly divided by the four elements, earth, wind, fire, and water. The majority of shinigami can only summon two or three shikigami. The single exception is Asato Tsuzuki, who commands the power of twelve high-ranked shikigami. They include the following:
- The guardian of the West. As a human (though complete with a striped tail), Byakko is similar to Tsuzuki in his habit of skipping work to have a nap, and being very lively and exuberant.
- Suzaku: a red "firebird" or phoenix, the first we see in the anime. She is the guardian of the South.
- In GensouKai, Suzaku is a dark-haired, fierce-tempered woman. Since Kyoto, she has born a grudge against her fellow fire-type Touda for the part he played in assisting Tsuzuki in his latest attempt of suicide. She is devoted to Tsuzuki, as shown by her misguided attempt to protect him in Kyoto. She also loves to drink and eat just like Tsuzuki, who affectionately calls her "Nee-san".
- The guardian of the East. Souryuu is one of the strongest and most highly-ranked of the Shikigami, other than Kurikara. He is suspicious of newcomers to his realm, and perceives Hisoka as a threat to its stability to the point of attacking him. Despite once being close to Kurikara, after the civil war he used the power granted to him by the Golden Emperor in order to seal Kurikara away. He has two children: Koujin and Tenko, thunder and water shikigami respectively who also serve Tsuzuki.
- Genbu: the black tortoise/snake, the guardian of the North.
- Genbu appears in human form as a tiny old man who is generally held in contempt by servants for his strange behavior. Nevertheless, he has on occasion offered advice to both Tsuzuki and Hisoka.
- Kouchin: A court musician who spends her time flirting and playing music, though she displays some knowledge of the civil war in Gensoukai.
- Rikujo: An astrologer shikigami and Genbu's student with several pairs of eyes on his hands and face. He appears to have a confrontational relationship with Souryuu.
- Taimo: A spellbreaker with a completely blank face who occasionally offers advice to Tsuzuki.
- Tenko: The daughter of Souryuu, and Kijin's younger sister. She is a water shiki.
- Kijin: The son of Souryuu, and Tenko's older brother. He is a thunder shiki.
- Daion: A gag shikigami who lives in a pot that has a mouth and eyes cut into it.
- Tenku: A large shrine that the others dwell in who also served as Touda's prison prior to Tsuzuki's arrival. He is shown to bear a grudge towards the former.
- Touda: a huge, black, winged serpent. The only shikigami capable of destroying a shinigami.
- When in human form, Touda wears a visor over his eyes to inhibit his powers. He does as Tsuzuki asks, but only exactly as he asks. Nonetheless, he is devoted in his own way to Tsuzuki, who freed him from eternal imprisonment within Tenku for unknown crimes. It is suggested that his crimes were actually missions the Golden Emperor assigned him privately, then punished him for publicly. He vowed to help Tsuzuki since it was the only way out of his imprisonment and agreed to wear the visor that also seems to alter his memories as well as limit his strength.
- Kurikara: a fire dragon type. Thought to be the most powerful shikigami in all of Gensoukai.
- In his human form he a very short male with the typical long ears of the dragon types and a scar that runs down the center of his forehead, and a second one that runs over his right eye from wounds that Souryuu inflicted on him. He and Souryuu used to be very close friends until after the civil war when the latter sealed him away. It is later revealed that he chose to defend humans against the Golden Emperor during the war, though he tells Hisoka that he hates them. The latter is currently attempting to gain him as one of his own shikigami. It is thought that Kurikara is a large black steel dragon.
There are two other characters who have shikigami: Hisoka Kurosaki and Hajime Terazuma.
-Hisoka is in control of a small, first level water Shiki named Riko. He can contain water in his body and spray it at will, and enjoys singing into a microphone and speaking bits of Spanish and English. He died protecting Hisoka from an enraged Kurikara. Hisoka then tried to attack Kurikara, but was stopped by Kotaro.
-Terazuma carries the only known example of a parastic type of shikigami, KaGanKokuShunGei. It roughly translates to 'Red-Eyed Black Lion'. When he is touched by a girl or a boy who looks girly (Hisoka), he transforms into a raging black beast that breathes fire. The beast is only contained by Wakaba's quick action slapping sealing fudas on its forehead, and she has admitted that she can only seal 'Kuro-chan'two times in a row per day. Because of Terazuma's practical non-existence in the anime, its form is never seen on screen. Tsuzuki stated that a bad match between a parasitic type and its host results in markings and other irregular deformities of the face, eyes, or teeth. This leads one to presume that Terazuma is a prime example of a 'bad match'.
- For dragon shikigami, they use their hair length as a way to measure each others strength. The longer the hair the more power they possess, the shorter the hair the less power possessed.