The Kaiba brother's pendant is a set of lockets made by Mokuba Kaiba for himself and Seto Kaiba. While Seto was in a coma, having been Mind Crushed by Yugi, Mokuba was told that Seto was reassembling the puzzle of his heart and would reawaken once he'd solved it. Taking a picture of himself and Seto playing chess in the orphanage that had been torn in two, Mokuba placed it inside a set of lockets, whose doors were fashioned after the backing of Duel Monsters cards.