Diamond, nicknamed Dia, is one of the two male protagonists in the DP series along with Pearl. Slow and dopey, he plays the role of the funny man in the Manzai standing comedy which he and Pearl practice. He usually adopts a happy-go-lucky attitude and follows Pearl's lead and decisions, but actually has his own opinions, especially when it comes to matters that stir up his emotions. This is a reflection of the virtue he represents: emotion, making him the most associated with Mesprit of the Sinnoh lake trio, the emotion Pokemon. In contrast to Pearl, Dia's character is relaxed and carefree, and according to Pearl, has never ever broken out in a rage, except the one clash he had with Pearl at Celestic. His gentle nature is interestingly opposite to the diamond, and is more comparable to the pearl, which has an ultimate smoothness.
Diamond is a character in the latest series of the Pokémon Special manga in Japan, based on the main male character from Pokémon Diamond and Pearl. His appearance is based on the Diamond and Pearl Male character, Lucas. He started out with a Munchlax called Bee. He is twelve years old.
Diamond is a good friend of Pearl and the pair form a Pokémon comedy duo, with Diamond acting as the boke (funny man) of the pair. Though seemingly dim-witted at first and possessing a perpetual habit of eating wherever he goes, Diamond is somewhat smarter than he looks. He stands up to foes in times of distress, and has been shown to be observant in a mishap involving wild Bidoof.
Due to a mix-up, Diamond believes that he and Pearl are on a reality television series; if they successfully escort Ms. Berlitz to Mt. Coronet, they will receive a prize (this is untrue, however, as Diamond has suspected something was wrong since the beginning, and chose to stay silent so that the journey could continue). Berlitz, believing the duo to be her bodyguards, gives them Pokédexes, Pokétches, and starter Pokémon from Professor Rowan. Diamond receives a Turtwig from her and nicknames it Rū. Rū has now evolved into a Torterra. He has also recently obtained a Shieldon named Puu.