Diamond grew up in Twinleaf Town with his best friend, Pearl. He and his Pokémon Lax (a Munchlax) eat at any chance they get, usually at inopportune moments. He also has a near-unhealthy obsession with the television show "Taurina Omega". (Protean Omega in English)
Diamond and Pearl enter a comedians' contest in Jubilife City and win a prize. They go to collect their prize and are accidentally mistaken by Platinum to be her appointed bodyguards because they happen to be wearing the right color scarves. At the same time, they think that she is a tour guide taking them on a trip of Sinnoh as a prize for their comedic skill.
Diamond and Pearl work for Professor Rowan, investigating legendary Pokémon. Dr. Footstep travels with them because he wants the legendary Pokémon's rare footsteps, and Diamond wants Dr. Footstep to look at Gi's footsteps when Gi finally decides to leave its pokéball. The Sinnoh Chairman of the Pokémon Association also teams up with them.
The four split into two groups, Diamond and Pearl, and Dr. Footstep and the Chairman. Diamond and Pearl go to look for Rotom because they had previously met Rotom. They go to the Old Chateau, where they encounter Rotom. Rotom defeats them and runs off to the Galactic building in Eterna City.
Diamond and Pearl use the Secret Key they found in the Old Chateau to get into the Secret Room of the Galactic building. Rotom attacks them in its various forms, blasting them through the wall. Pearl rushes off to the Old Chateau to get Rotom's harmless TV while Diamond continues to fend off Rotom. Diamond sees Rotom mow the lawn in the shape of Diamond's face; Diamond befriends him. By the time Pearl returns, Rotom has decided to go with Diamond.
Diamond really likes eating and sleeping. He is also very compassionate and kind.
His interests are mecha anime and games. His skills are cooking and making poffins.
Mamoswine was given to Diamond by Platinum.
Pearl is Diamond's best friend. They share the dream of becoming comedians together. He often gets smacked by Peal at the end of their comedy routine.
He admires Platinum.
- All of Diamond's Pokémon are male
- Except for Gii, who is genderless
- His blood type is A
- He (and Pearl) have won the New Era Comedy Grand Prix "Daibaku Show" Judges' special prize
|Red/Green/Blue Arc||Red | Blue | Green|
|Yellow Arc||Yellow |
|Gold/Silver/Crystal Arc||Gold | Silver | Crystal|
|Ruby/Sapphire Arc||Ruby | Sapphire|
|Diamond/Pearl Arc||Diamond | Pearl | Platinum|
|Heart Gold/Soul Silver Arc||Gold | Silver | Crystal|
|Black/White Arc||Black | White | Cheren | Bianca|
|Black 2/White 2 Arc||Blake | Whitley|
|X/Y Arc||X | Y|
|Sun/Moon Arc||Sun | Moon|