Friendship Heart

The Friendship Heart is a magical artifact in Pocket Kingdom. It allows users to manipulate magic, send beings from one world to another, allow humans to understand animals, and even attack others if needed.

Original (Red)
The original Friendship Heart was red and was in possession of Ava until it was broken in two by Soul when he attempted to steal it for Eva. Later on, Kate and Magic restore the heart by recovering the second piece from Eva and put it together, and are allowed to keep it when Ava manifests a new, blue variant. Magic wears it on his collar most prominently and is able to travel to and from Earth at will with it, even without Kate.

Blue (Ocean of Friendship)
When Ava is returned to Pocket Kingdom, she manifests the blue variant for her own use so Kate and Magic can keep the original. She uses it for the next three years until the Petbuster uses his zap gun on her at a lethal setting, the high voltage killing her and shattering the blue heart in two. This time, the heart is seemingly broken permanently and cannot be restored by simply combining both parts. William wears the taped heart on his collar and pursues the Petbuster with Danny, Magic and Pally. The four each show different values of friendship on their journey, igniting light magic and allowing the broken blue heart to secretly absorb it. When the four return to Pocket Kingdom. the absorbed magic, as well as Ava's strength in magic, allow her to be resurrected, and the blue heart is finally restored. Ava allows William to keep the blue heart.

The blue heart was named the 'Ocean of Friendship' in the TV Show, and was first mentioned by this name in VIII: The Ultimate Choice.

Purple (Ornament of Friendship)
After Ava's resurrection, she allows William to retain possession of the blue heart and manifests a new, purple variant for herself, which she is still in possession of. She was able to manipulate magic with it to stop a deadly thunderstorm. The purple heart was officially named the 'Ornament of Friendship' in VIII: The Ultimate Choice.

Black Heart
The Black Heart is the opposite of the friendship heart, and is instead used to channel dark magic and negative emotions. It was in possession of practioners of dark magic, but was later locked away after Ava's ancestors gained possession of it, but has recently been stolen, presumably by Eva.