Junkers is a miniature schnauzer possessing supernatural abilities, chiefly the power of human speech and the capacity to grant exactly three miracles per family. He maintains the appearance of an ordinary dog to most humans but communicates verbally with specific individuals. The origins of his magical traits remain unexplored across official media.

In the 1994 OVA "Memories of You," Junkers befriends the Arimura sisters following their parents' death. He demonstrates his powers by restoring a broken tree and swing at their residence. The sisters then use two wishes: one to accelerate a romantic relationship for the second-oldest sister, and another to regrow a tree holding maternal significance. Junkers independently expends the final wish to restore their amnesiac mother's memories after the sisters decline to use it. He accompanies the family to Paris and later facilitates the mother's reunion with them.

The 1995 film depicts Junkers as the companion to Hiromi Nozawa, a girl dealing with parental absence and potential divorce. He reveals his three-wish ability during her emotional distress, acting as her primary confidant. His conversations with Hiromi remain private and unnoticed by others. The film portrays him as a stabilizing presence during family upheaval, though the specific outcomes of his miracles are not detailed. His personality includes a relaxed demeanor and an appreciation for samurai television dramas.

Consistent across both narratives are his role as an emotional anchor amid familial crisis, strict adherence to the three-wish limit per family, and selective verbal communication with humans. He exhibits self-assuredness, referencing his own "cool personality." His fundamental nature shows no evolution or alteration in either story.