Jessie/Anime/Main series/History/Pre-series

Jessie's mother, Miyamoto, was a high-ranking Team Rocket agent. When Jessie was around the age of five, Miyamoto left on a mission to the to record the voice of the elusive Pokémon. However, after Miyamoto disappeared, Jessie was put into a foster home which had very little money. There were times when she had no choice but to eat snow because of a lack of food. As Jessie was very small then, she did not know she was poor and thought eating snow was an enjoyable thing to do.

In Crossing Paths, it was revealed that she had a crush on a boy she had gone to school with, named Astin, who was leaving to become a Pokémon Coordinator, and who has a current-day counterpart with a similar name. She refused to go with him because she and two friends were training to become pop idols. Unfortunately, while her two friends passed, Jessie's audition didn't go well and her idol dreams were quashed. When she was old enough, she left home to become a Pokémon nurse. However, she was unable to go to a regular nursing school and went to the Pokémon Nurse School, which was intended for. She was quite skilled at things such as bandaging, and even showed a Chansey how to do it. She quickly became good friends with that Chansey. However, because she was not a Chansey herself, Jessie couldn't do things like use to soothe Pokémon, instead falling asleep herself. Ultimately, she failed to graduate, and on graduation day, she simply packed a bag and left. As she was leaving, Chansey came up to her and offered her her nurses' hat, but Jessie refused to take it. Chansey then broke her egg-shaped pendant she got as proof of graduating in half and gave one half to Jessie so that they would have something to remember each other by. In the episode Ignorance is Blissey, Jessie was reunited with that same Chansey, which had since evolved into a.

In The School of Hard Knocks, Jessie and James told that while they were at the Pokémon Trainers' school Pokémon Tech, they both received the lowest scores in the history of the school. The school later brought back bad memories for both Jessie and James.

After this, as revealed in The Bridge Bike Gang, Jessie and James joined a bicycle gang in Sunnytown, where Jessie was known for swinging a chain above her head as she rode her bike, acquiring the nicknames "Big Jess" and "Chainer Jessie".

It was revealed in Spring Fever that she was supposedly a model at one point.

Upon arriving at Littleroot Town's port in Hoenn Alone, Jessie indicated that she had been to the town sometime before and referred to it as "the city whose colors will never change", though she didn't elaborate further.

Sometime before joining Team Rocket, Jessie obtained a Contest Pass in the Hoenn region. Also during the years before Team Rocket, she had several boyfriends, all of whom left her and/or treated her badly. In Xatu the Future, she revealed that she had once worked at a TV station as the weathergirl. In From Cradle to Save, it was revealed that she once was a ninja.

Due to conflicts in canon between Kanto and Johto episodes and the special episode Training Daze, what happened between Jessie and James after the bike gang is unknown. What is known, as shown in the special episode, is that they joined Team Rocket separately and were on initially unfriendly terms after being grouped with Meowth but they quickly made up and became good friends.

Team Rocket member held a grudge against Jessie for failing to pay for a drink (making Wendy pay), but got her revenge when she added the charge to Jessie's overall Team Rocket bill. (However, Jessie revealed to Meowth and James later on that she didn't even like fruit smoothies for some reason.)