Unshelltered is an egg-like Yo-kai with thin arms and legs. He has green eyes with white irises. He has a large crack on top of his head and a red swirl on his belly.
Unshelltered has the ability to help Yo-kai break out of their shells, using various techniques to do so, even resorting to becoming a thief.
Like certain Yo-kai, Unshelltered was once a human, one who was not very confident in himself, and tried to break free of his "shell". But before he could, he lost his life in a tragic accident when he fell down a tall flight of stone stairs when he twisted his ankle upon a misstep.
In order to help out Yo-kai in his own view, Unshelltered reinvented himself as the Phantom Thief Kopin (Japanese: 怪盗コパン,Kaitō Kopan) and began a spree of robberies centered around a Yo-kai's sense of identity that ended with him returning the stolen items back to Inaho Misora and USApyon, yet he had always managed to elude the duo. His luck finally ran out and his real identity was revealed when the duo finally cornered him when he slid on a banana peel after he had stolen and returned USApyon's suit.
When he gave his story and why he had done everything, Inaho and USApyon decided to help him literally break out of his shell, though USApyon had to prevent Inaho from using a hammer, but they ended up ending the egg Yo-kai after they peeled Unshelltered apart five times, with him getting smaller and smaller with each consecutive peeling until there was nothing left. After a moment of panic, USApyon and Inaho scooped up Unshelltered's shell fragments into trash bags and placed them outside for garbagemen to deal with them.
After this, the InaUSA Detective Agency officially shut down, most likely resulting in large protests from other Yo-kai who still needed help.