An only child of millionaires, James was forced to endure formal society while growing up. Often having to take part in numerous lessons and activities he had little to no interest in, he eventually began to grow weary of the rules and standards that appeared to be ever-present within the upper-class. He presently enjoyed visiting his Nanny and Pop-Pop and his only real friend among the estate was his pet Growlithe, Growlie.
At young age, James got fed up with the formal balls that his parents would host, when on one of these balls, he met a girl named Jessiebelle that he developed a crush on. He wrote his feelings for her in a letter and his parents gifted him a tresure chest to put it in and give to Jessiebelle to make sure no one read it before she did. However, when he paid her a visit that night, she revealed they had been engaged and demanded that James replaced Growlie with a Skitty. He refused and fled, realizing how selfish Jessiebelle was. He forgot what the password was and so he had Growlie bury it with Dig near one of his summer estates in the Sinnoh region. Jessiebelle refused to leave him alone, so he and Growlie ran away.
James collapsed in a street and sent Growlie home where he joined Pokémon Tech and met Jessie. They both flunked out and joined a Bicycle gang on a bridge near Sunny Town together. Eventually, Jessie, James and the bike gang went their seperate ways.
James then joined Team Rocket and was partnered up with Jessie. They were then partnered up with Meowth under unfriendly terms that ended up with James getting injured in an accident of falling off a bridge in order to save Meowth. However, he promised never to let Jessie down and rejoined the trio. Jessie and Meowth helped him in a mission where they almost succeeded in capturing the legendary Red Snorlax. They then graduated from the Team Rocket Training Academy and became the Team Rocket trio.
Jessie and James were bother temporarily mentors to Christopher. He also recieved a Koffing for christmas.
In Holy Matrimony!, Jessie and Meowth forced James to accept his parents' mansion for profit, but this was simply a trap to force James to marry Jessiebelle. Luckily, Growlie came to his rescue and they managed to escape. James stated he was happier living with Team Rocket than having millionares as parents and rejoined the trio, leaving Growlie behind once again.
He has a habit of getting fooled into buying worthless Pokémon by a Magikarp salesman. James also captures a Weepinbell that he leaves at a fake breeding center, leading it to evolve into Victreebel. It has a habit of biting him on the head.
In Johto, James is forced to Trade his Victreebel away for a Weepinbell that has a special Sweet Scent to attract other Pokémon to get ahold of Larvitar and Elekid. To his dismay, it evolves into Victreebel and bites on Jessie's head which forces her to toss it away using Arbok. James uses bottlecaps to create a stand during the Silver Conference.
In Hoenn, James is forced to let go of Weezing to protect a group of Koffing, but then gains a new friend in a Cacnea he befriended earlier. At Fortree Cty, he fails to win a Chimecho at a festival and then buys a fake Chimecho from the Magikarp salesman, but it is revealed to be a Hoppip. He then successfully gets a real Chimecho, which he wanted ever since he was a child.
During this time, James visits his grandparents because Chimecho is sick. He leaves it with them at the same time as May's Munchlax is as well and they take a truce with James. During the truce, James befriends Nanny and Pop-Pop's friend Mime Jr., which Jessie and Meowth steal in their backup plan. James uses Cacnea to beat Jessie's Seviper and then leaves Chimecho behind. Mime Jr. then hops into an empty Poké Ball and replaces Chimecho as James's Pokémon that hops out of its Poké Ball.
In Sinnoh, James visits his second summer cottage and finds his beloved Carnivine that he captured in the Pastoria CityGreat Marsh. However, Mr. Cheese informed him that he had rung his entire family and that his parents and Jessiebelle were on their way. This forced the trio to withdraw from the summer cottage. However, James brings Carnivine along with them.
Soon, he is forced into a Tag Battle with Gardenia against Ash and Dawn and Gardenia gets him to use Drain Punch after seeing Cacnea use Needle Arm. However, it fails a second time and James attempts to train Cacnea to learn Drain Punch. However, the training fails and James is forced to give Cacnea to Gardenia. Jessie and Meowth attempt to calm his heart and it succeeds.
Later, Ash uncovered James's old treasure chest and James, not realizing it was the same treasure chest as the one he buried as a child, attempted to steal it with Jessie and Meowth dressed as pirates. Pikachu shocked them with Thunderbolt which caused James to remember and after a failed attempt to open the chest, remembered the letter. He tried everything to get ahold of it, even disguising themselves as Jessiebelle and her men, but eventually after Growlie blew the disguise, he got ahold of it. He explained what happened years ago and then Jessiebelle arrived. He escaped and they managed to destroy the chest by sending it "blasting off". Jessiebelle came into attemptation to force James to marry her, but James ordered Ash to use Thunderbolt on them. They then blasted off, unintentionally bringing Jessiebelle with him, but he managed to escape her.
In the Best Wishes series, the trio became more serious and less goofy, going to Unova for a project involving the Meteonite, in which they happened to run into Ash on the way. They then decided to catch Pikachu, but then decided to follow orders and using a meteorite stolen from the Nacrene Museum, they found the Meteonite in the Desert Resort. However, due to Ash's inteference along with Team Plasma's, events caused the project to be cancelled.
Matori informed them that they would not be needed for any more missions, so they went back to their white uniforms and Agent status. James found a Yamask in a warehouse in Castelia City and made friends with it, giving it food and then captured it. Since then, the trio have been summoned by Dr. Zager for missions across Unova, such as using the Nimbasa Subway to steal all the Nimbasa City Pokémon Center Poké Balls, capturing the Kami trio on Milos Island and using Fujio's Carracosta. However, Ash has thwarted all of these plots.
James has a habit of owning dangerous Grass-typePokémon, such as Victreebel, Cacnea and Carnivine, all of which are pleasent to Gardenia. These Pokémon also have a habit of attacking James when emerging from their Poké Balls. Also, James has a hard time when having to let his Pokémon go, such as when he was forced to Trade his Victreebel away.
James met Yamask in Castelia City, where it found some food in the Team Rocket suitcase. Jessie attempted to catch it with Woobat, but James opposed this and gave it food. They then became friends and James captured it in a Poké Ball. It has become his only Unova region Pokémon at this point.
Mime Jr. befriended James at his Kanto summer cottage while he was staying there during the time of which his Chimecho was sick. At the end of the episode, Mime Jr. decided to join James and hopped inside its Poké Ball.
James was forced to leave Mime Jr. at Team Rocket HQ because Mime Jr. are not native to Unova and using it in Unova would attract too much attention.
When the Team Rocket trio came to Sinnoh, they found James's summer cottage and James uncovered Carnivine inside a case of old bottelcaps, but James was forced to leave when he heared Jessiebelle was on her way. He brought Carnivine with him on his treak around Sinnoh. It has a habit of biting onto his head.
James was forced to leave it at Team Rocket HQ because Carnivine are not native to Unova and using it in Unova would attract too much attention.
James befriended a wild Cacnea in Hoenn before he released his Weezing. He gave Cacnea a bag and after releasing Weezing, Cacnea returned and gave the bag back. James then captured the Cacnea. It has a habit of hugging him, where its spikes cause him intese pain.
In Sinnoh, Cacnea befriended Gardenia, the Eterna CityGym Leader and a few episodes later, Gardenia advised James to teach Cacnea Drain Punch after seeing it use Needle Arm. James then failed to teach Cacnea Drain Punch and gave Cacnea to Gardenia to learn Drain Punch, which they succeeded in doing.
Growlie stayed at one of James's summer estates in The Treasure Is All Mine!, and James came to the estate to get ahold of his old treasure chest. Growlie brew his cover and it obeyed James in the battle against the chest. It was left behind again after James blasted off to escape Jessiebelle.
James wanted a Chimecho since he was a child and after two failed attempts to get one, he finally got a Chimecho that joined him through the rest of the Hoenn saga in Fortree City. It has a habit it wrapping around his head and causing him lots of pain.
In Kanto, he left Chimecho with Nanny and Pop-Pop because it was so sick it couldn't use its own moves. James was forced to leave it behind, but he has promised to come back and get it when it is better.
James bought Gyarados from the Magikarp salesman as a Magikarp. He was tricked into thinking it would lay other 100 Magikarp eggs and that would result of him having a 100000 Magikarp to sell for 100 dollars which would lead into him having a billion dollars. James purchased Magikarp for 300 dollars, plus Jessie's and they revealed its Poké Ball was just gold-plated. It was the main reason they got sunk on the St. Anne, due to James attempting to catch it.
In Pokémon Shipwreck, James called upon it to escape the sinking St. Anne, but it just made the situation worse. James then got angry with it because it couldn't swim and wasn't even good for eating. He then kicked it into the ocean, which caused it to evolve into Gyarados and get angry at James. It then joined a group of Gyarados and used Dragon Rage, sending them flying into Pokémon Land.
Hoppip was purchased from the Magikarp salesman, tricked into thinking it was a Chimecho, which James had wanted since he was a child. He then rubbed it and it fell apart, revealing it was just a Hoppip. It then floated away, never to be seen again.
Several Numel were seen in a flashback in Game Winning Assist, where he claims he used to have them heat his bed as a child. However, it is unknown if he owned the Numel or if he joust befirended them or if they are still at his parents' house.
While he has not accomplished much as a member of Team Rocket, James has proven to be quite skilled at several other pursuits. He has performed well in a few side competitions, even winning a Pokémon Contest.
Their final appearance is at the Silph Co., where they once again protect Giovanni from Red while he is trying to take the newly-invented Master Ball from the president. Weezing is at level 31, and can use Tackle, Smog and Sludge. Red beats them and they are not seen again.