Movie 1: Digimon Adventure
"Two children receive a strange egg through their computer, which hatches into their very first Digimon, leading to the night that would change their lives forever." (Digimon Wiki)
In the first movie Kari is still a very little child. She is actually the one who discovers a DigiEgg from her father's computer. In the middle of the night Tai went to the toilet and he found Kari in his father's room. She was looking at the computer monitor and then suddenly the egg came out of it. The next morning Tai saw Kari sleeping with the DigiEgg and he was kinda shocked because he thought that this was just a weird dream. In the first movie Kari didn't talk that much but she used her whistle to communicate. Kari is much more interested in Digimon than Tai is (in this movie). She took care of the egg and she was always around it.
When Botamon hatched out of the DigiEgg Tai was really scared of it because he didn't know what that is. But Kari wasn't. She was really nice to Botamon which was really scared of her and Tai. But Kari managed to gain his trust. Kari really took care of Botomon, she fed him so that's why he digivolved to Koromon. He was hungry and Kari and Tai didn't have any food at home so Kari took Miko's (their cat) food and gave it to Koromon. Miko didn't really like that so she attacked Koromon and later Tai when he tried to protect Koromon.
Later that night Koromon was acting really weird (because he could feel another evil Digimon). Kari woke up Tai and showed Koromon to him. Koromon digivolved to Agumon (he was really huge as Agumon). Agumon wanted to go out so Kari opened a window for him and she climbed on him. Agumon jumped through the window together with Kari. They were walking around the Hikarigaoka and meanwhile Tai was looking for them. The location they were at is actually real. Agumon destroyed a few things because of that night. Agumon started attacking cars and Kari begged him to stop. He did because he saw some planes and he started to chase them. A few seconds later a new DigiEgg arrived in the sky. From that DigiEgg Parrothmon came and Agumon started to fight with him. Tai finally found Kari and he wanted to take her with him but Kari didn't want to go. She wanted Agumon to stop. When Parrothmon attacked them Agumon protected Kari and Tai and also digivolved to Greymon. Parrothmon and Greymon started to fight and Greymon was losing. When Greymon was just lying there and couldn't move Kari wanted to help him. Kari tried to wake him up with her whistle. She couldn't do it because she was crying and she couldn't blow in the whistle. Tai took the whistle from her and woke Greymon up. He defeated Parrothmon and they both went to the Digital World. Kari was still searching and screaming for Koromon but he wasn't there anymore.
Movie 2: Our War Game
"When a deadly virus Digimon causes mass havoc on the Internet, it's left up to just a few of the DigiDestined to stop him, and save Tokyo from an incoming missile attack." (Digimon Wiki)
Kari is here just for the funny movie scenes, she doesn't play any important role. They are the same age as in season 1. In the beginning Tai was writing an email to Sora (because she was mad at him and he just wanted to apologize). Tai added a heart at the end of the email by mistake. Kari came to Tai and she saw that he was writing an email. Tai blocked the monitor with his hands because he didn't want her to see the email. Tai noticed that Kari was dressed up really nice and he asked her where is she going. She said that she'll go to a birthday party of a friend. Kari showed him the present for a friend and Tai wanted to have it. When Tai gave up Kari went to the computer and sent his email. She wanted to know for who the email was but Tai didn't want to tell her.
Later when Tai called Kari we found out that she was at a birthday party at Hori's family. The birthday girl wanted to blow out the candles and she stopped because Kari was on the phone with Tai. He told her to come home as soon as possible. Right when they want to blow out the candles.
After a while Tai called Kari again because he wanted her to come home and help them with fighting Diablomon. Kari and her friends were playing with the cards when Tai called. Kari said that she can't leave because she's winning.
The third time when Tai called Kari he left a message for her to come back home. But she didn't. In the end everything went well and in the end we can see a picture of Kari and her friends at the birthday party.
Movie 3: Hurricane Touchdown
"The DigiDestined kids discover another one of their kind living in the United States, who's own Digimon falls victim to a powerful computer virus." (Digimon Wiki)
Kari went to New York together with T.K. to visit Mimi. The three of them are sending some pictures probably to Davis so that he would be jealous (on one picture there are Kari and T.K. together). Mimi and T.K. were joking about it but Kari wasn't in the mood. She felt a crying Digimon somewhere in the near. A Digimon that is searching for something. Suddenly Mimi disappeared to another world – an unknown world. Kari still felt this sad Digimon near them so T.K. and Kari went searching for him. They found him and an American DigiDestined - Wallace. When Wallace noticed them he ran away. Kari suddenly heard Tai's voice. And they both knew that Wallace and his Digimon have something to do with it. Kari sent an email to Davis who is on a holiday together with Yolei and Cody and she asked him to save her brother.
Kari and T.K. traveled by train to meet Davis and others. I think that T.K. wasn't really happy when he heard that Davis is coming to meet them. Suddenly Kari's D-3 digivice started to blink. Everyone disappeared and they were all alone on the train. Even the train stopped. Because of that they needed to take a bus to Summer Memory.
In the middle of the fight with Chocomon Kari and T.K. finally arrived and their Digimon saved Veemon and others from being eaten by Chocomon. Even Angewomon and Angemon didn't have much luck with Chocomon. He changed the world in a dark place. They all changed to their younger self. Angewomon and Angemon both digivolved to their mega level (Seraphymon and Holydramon). But they couldn't defeat Chocomon even if they were mega level.
After Magnamon and Rapidmon were possessed by Chocomon, Gatomon and other Digimon attacked Chocomon because they wanted to save them and they were really optimistic about it. They save them and Rapidmon and Magnamon defeated Chocomon.
In the end they had to go back to Japan and before they went home Wallace kissed Kari and Yolei on the cheek. That made Davis really jealous.
Movie 4: Diaboromon Strikes Back
"Diaboromon makes a return to the net, and the DigiDestined are quick to act, unaware that Diaboromon has a couple more tricks up his sleeve since their last encounter." (Digimon Wiki)
Kari went to the DigiDestined meeting. They all came - also the DigiDestined from season 1. Izzy showed some pictures that were spreading around on the internet to them. On every single picture it was one of them. This was all work from Diablomon. They thought they destroyed him but they didn't. His data survived. Diablomon started sending Kuramon to the real world through the emails.
Tai and Matt decided to go through the gate to the net and defeat Diablomon. Kari was really scared because of that. But Gatomon managed to calm her and she told her that everything will be alright. Izzy wanted the rest of them to go and capture all the Kuramons. Kari and Yolei went together to catch them. They should use their D-3 digivice and send them out of the real world. Kari and Yolei didn't have any problems with it.
Tai and Matt were having a few problems with Diablomon on the net so that's why Kari and T.K. went on the net too. To help them. Gatomon evolved into Angewomon. They were all on the big screen at Shibuya and also Diablomon sent emails around with the happenings inside. They did pretty well inside the net but that was actually Diablomon's plan.
When T.K. and Kari get out of the net they went to the computer room and they watched the whole thing through the window. When Omegamon lost Kari was really scared and worried. Later when Imperialdramon lost too, Omegamon gave him his power and from everyone so that he could evolve into Paladin mode. He gave him his power through the holy ring and Kari recognized the holy ring. When Armagemon was defeated Kari heard her whistle from a several years ago (the scene we see in the first movie).
Kari was really happy when they defeated him.
Digimon Adventure: Last Evolution – Kizuna (デジモンアドベンチャー Last Evolution 絆)
"Five years after the events of Digimon Adventure tri., Tai and the other DigiDestined are approaching adulthood; however, Tai and Matt still remain undecided about their future goals. The DigiDestined later meet Menoa Bellucci, a professor at Columbia University in New York City, and Kyotaro Imura, her bodyguard. Menoa claims that Eosmon is targeting DigiDestined around the world by robbing both them and their Digimon partners of their consciousness. With Menoa's help, Tai, Matt, Izzy, T.K., and their Digimon fight Eosmon on the Internet." (Digimon Wiki)
The movie starts with news about a possible aurora and Parrotmon coming to the real world, causing a car crash. Kari and Gatomon try to protect the people and the city, attempting to bring Parrotmon to the open digital gate with the help of Izzy, Tai, T.K., and later Matt. They manage to save the city, and afterward, Kari, T.K., and their Digimon, along with Matt and Tai's Digimon, go out to eat.
Even though Kari is part of the original kids, she is still a side character in this movie. After a while, Izzy gets an email titled "Who is next" with a link to a video showing an unconscious Kari and T.K. tied to chairs. Tai goes after Kari's location, and Matt goes after T.K.'s. The two of them lost consciousness like a few other Digidestined before them. Now Tai and Matt need to find a way to bring them all back, even though fighting with their Digimon could mean losing them forever.
Throughout the movie, they discover that Menoa is the villain, creating an artificial world where she keeps all the Digidestined in their child form so they never grow up and are never parted from their Digimon partners. When Tai arrives there, Kari is already present.
While Tai and Matt try to save all the Digidestined from this fake world, Kari and the 01 kids company, under some kind of spell, attacks them for trying to destroy the world. When Tai manages to blow Kari's whistle, they all return to their normal selves and help Tai and Matt defeat Menoa.
That's pretty much Kari's whole story in this movie. We see her in the credits scene enjoying some coffee or cocoa with Gatomon in a café.
Digimon Adventure 02: The Beginning (デジモンアドベンチャー02 THE BEGINNING)
"Two years after the battle against Eosmon, Davis Motomiya, Ken Ichijouji, Yolei Inoue, Cody Hida, T.K. Takaishi, and Kari Kamiya meet a boy named Lui Ohwada, who is found with a depowered Digivice and claims to be the first DigiDestined ever. In addition, a Digimon named Ukkomon appears in the real world, who wants every person in the world to have their own Digimon partner." (Digimon Wiki)
At the beginning of the movie, in the opening scene, we see Kari at the daycare where she works while studying. At the end of this scene, the 02 kids meet at Davis's ramen shop to discuss the giant Digimon egg floating above Tokyo Tower. Kari, along with the others, watches the news and sees Tai at work.
Later, when they come into contact with Lui, Kari wants to know if he has anything to do with the Digimon egg. They all want to understand what's going on. Lui shares his life story, and the trio (Davis, Ken, and Lui) try to talk to Ukkomon. When they time travel by falling through the Digimon egg and return, Kari and the others are waiting for them. Together, they run away from the police who saw them near the Digimon egg.
The kids hide in a computer room to review everything they know—what's happening, the relationship between humans and Digimon, and Lui and Ukkomon's history. Kari is the first to express empathy for Ukkomon, showcasing her compassionate nature.
When Ukkomon tries to get every human their own Digimon, they all disagree on the next steps. T.K. fears he will lose his bond with Patamon if they attack Ukkomon, but Kari and the others are confident in their bonds with their Digimon and want to confront him. They convince Lui to talk to Ukkomon, hoping to resolve the situation without fighting.
While Davis and Ken go with Lui, Kari and the rest of the 02 kids head to Tokyo Tower in T.K.'s car to assist if needed, which they do.
After defeating Ukkomon, it starts snowing, and Davis initiates a snowball fight in which Kari also participates. The movie ends with them having fun like children.