Zuijin
In Shinto, Zuijin are Kami warrior-guardian figures, Kami that guard over shrine gates are considered to be Kado-Mori-no-Kami or Kadomori-no-Kami, the gods who watch over the gates. They're often depicted as holding bows and arrows or wearing three silver rings. It appears on glass-like materials. The name was originally applied to the bodyguards of the Emperor of Japan. Statues of Zuijin are now often placed flanking shrine gates, similar to the Niō and Gozu and Mezu. The Zuijin are also associated with Dosojin, protector of crossroads and other boundary areas.
History
Zuijin was a government official in Konoefu during and after the Heian period; zuijin followed nobles to guard them when they went out.Yadaijin
Yadaijin is one of the two deity statues in Zuijin costumes that are placed at the both sides of Zuijin-mon gate, holding bows and arrows on the observer's left.Kadomori, a guardian deity at the shrine gate.
He is dressed in Kettekino-ho, putting on Kenei no kanmuri with Oikake, wearing a sword, holding bows and arrows.
He is called Yadaijin after his arrows, and Zuijin-mon gate is sometimes called Yadaijin-mon gate.
However, he is not a Daijin but a Zuijin called Kadono-osa.
Also, he is referred as Amanoiwatowake no Kami. Or it is said that the image of Yadaijin comes from Amenooshihi no Mikoto and Amatsukume no Mikoto in the lead, removing Amenoiwahagi, holding Kabutsuchi-no-tachi, 天波十弓, and 天真児矢 at the time of Tensonkorin.
Sadajin
On the right of the observer is Sadajin, the elder left hand man. His attire is similar to Yadajin’s, with the same Kenei no kanmuri, Oikake, and weapons, including a large bow and arrows.The main difference between the two guardian deity statues is that Sadajin’s mouth is open, while Yadajin’s is closed. This is meant to symbolize the first breath in and the first breath out, a concept borrowed from Budhhist traditions.