From Bulbapedia, the community-driven Pokémon encyclopedia.
Diamond (Japanese: ダイヤモンド) is one of the male main characters for the Pokémon Diamond and Pearl story arc of Pokémon Special.
He is the funny man (boke) of the comedy duo, with Pearl as the straight man; however he is not as stupid as he looks. His appearance is based off of the male player character of Diamond and Pearl, Lucas. He is usually called Dia, but whenever Pearl is serious, he will call him by Diamond, his full name.
Diamond is often apathetic and rarely not seen eating, traits that he shares with his Pokémon. He is, while not fat, much less active or athletic when compared to Pearl. However, he is always serious when it comes to food and is an expert Poffin maker. Whenever something doesn't make sense to him, he'll try and figure out. Diamond has a somewhat natural instinct to judge how a Pokémon feels and can be quite observant when something perks his intrest.
A mix-up has them thinking they will gain a prize for escorting Platina to Mt. Coronet. Platina, mistaking them for her bodyguards, has given them Pokédexes, Pokétches, and starter Pokémon from Professor Rowan. Eventually, they are told the truth by Platina's real bodyguards, although Diamond knew long before Pearl that Platina wasn't a tour guide. He figured this out from various clues such as the fancy hotels, and Platina not actually acting like a tour guide.
Diamond has a large amount of respect for Pearl; the two are as close as brothers. Diamond also has a not-so-small crush on Platina.
However, Diamond has changed a lot from the beginning of his journey. He remains as the only Sinnoh trainer to have gained a Pokémon since the start of their journey. He was convinced by Pearl to set aside their dream of becoming great comedians to protect Platina until she finishes her journey after the incident in Veilstone City.
- Bē: Diamond's first Pokémon. Often seen eating with him and sometimes functions along with Pearl's Chatot to create a parody of Diamond and Pearl themselves.
- Rū: Received from Platina due to the mix up. Diamond's strongest Pokémon.
- Pū: First seen when Diamond begins traveling on his own.
- Rii: Received when Diamond was heading towards Lake Verity when it stold Diamond's Map.