Pearl is impatient and is often accidentally getting himself and his friend, Diamond into trouble. He is the straight man of the comedy duo, while Diamond is the funny man.

Compared to Diamond, Pearl is hasty and easily angered and, according to Diamond, always goes out of his way to complete things he has started, which reflects the virtue that he is aligned with: willpower, which also makes him associated with Agnome. Pearl is also very bossy and usually tells Diamond and Platinum Berlitz what to do. 

~!For his skills, he is given the title of "Determiner".!~

(Source: Bulbapedia)

Red is just a normal kid living in the rural Pallet Town, when he decides to go out on his own adventure, along with his rival since childhood, Green. In this world of Pokemon, he makes many friends, humans and Pokemon alike. However, all is not well. Team Rocket is trying to capture Mew, a very rare Pokemon, and is performing experiments on other Pokemon, trying to increase their power. Red and his friends must battle against Team Rocket to stop their cruel experiments and unlock the secrets of Pokemon.

Pokémon Trainers Pearl and Diamond are starstruck! Their lifelong dream is to floor an audience with their Pokémon comedy act. So how do they wind up as bodyguards to a pampered little rich girl on a quest to reach the peak of Mt. Coronet...?!
 
Come along and join the thrills and laughs as Pokémon Adventures continues!
 
Plus, meet Starly, Bidoof, Luxio, Combee, Bronzor, Rotom and many more Sinnoh Pokémon friends!
 
(Source: Viz Media)
 
In the Viz Media release, the Diamond & Pearl arc’s volumes were collected under the same title as the Platinum arc; this entry is exclusively for the Diamond & Pearl arc.

Finally together again, Dia, Pearl, and Platinum must battle Legendary Pokémon Dialga and Palkia, who are being controlled by Cyrus, the powerful boss of Team Galactic! Then a new Legendary Pokémon leaps into the fray! Whose side is it on...?
 
And who will rescue Platinum’s hapless bodyguards from the mysterious Distortion World they’ve been banished to...?
 
Plus, hang with Lopunny and meet Porygon-Z, Gallade, and... Looker?!
 
(Source: Viz Media)
 
In the Viz Media release, the Diamond & Pearl arc’s volumes were collected under the same title as the Platinum arc; this entry is exclusively for the Platinum arc.

A Special Music Video in tribute to the Pokémon Series of Games, set to the song Acacia by Bump of Chicken.