This is Broken.

He is a strange creature, one of darkness, yet one who feels warmth and goodness in his heart. He has lived his endless life possessing things to give himself a voice, one that will love, one that will stay by someone's side until they are gone forever. Broken has lived many lives, most of them having been lived through the body of a doll. His current life, the one we will be viewing, is lived through a doll resembling a Pokemon, the banette to be specific, the owner of this homemade doll is his best friend, and, despite the protest against this, he is her guardian and ally. Broken is one who, once emotionally attached to someone, will protect them with all he has, while he is clingy he is usually unable to handle himself alone, needing to know someone is there for him in order to be himself, otherwise becoming a mess, refusing to do anything other than stay in one place and wait, nobody knows what he waits for, not even himself, but he believes it could be waiting for when he can finally go to another world, where all his friends are waiting for him

and they will never leave again.