Doppelganger Technique(二重身術, Nijuushin no Jutsu) is a technique similar to the Shadow Clone Technique, that uses the effect of the Shadow Dimension Technique. Using this jutsu, Kaname is able to call his shadow by his side to fight alongside him. Like the effects of another jutsu when in use, he doesn't have a shadow. Like a normal clone, this doppelganger is able to use all of Kaname's technique, with the addition to being able to enter shadows at will in order to travel around the battle field.
If the Shadow Thief technique is used before this technique, the created Doppelganger will appear as the stolen shadow instead. In this case, the Doppelganger will have access to the opponents techniques instead of Kaname's. However, he still retains the ability to control it.
Much like Shadow Clone, Kaname is able to call it back to him which returns to being his shadow. Once returned Kaname will gain the information the shadow obtained during its time away. While this technique is active, he is unable to use the Shadow Dimension Technique and his dervied jutsu.