It is the year 2020 and computers have become an integral part of daily life for most people. However, a teenage girl Yui Kasuga is one of the few who cannot use computers at all, despite the fact that her father is a software developer. An evil computer called Grosser wants to take over the ComNet (what the Internet is called in Yui's time) and as the programs that have been developed to stop it (called "Correctors") need her help, she is sucked into the ComNet where she is recruited by a corrector called I.R., who gives her downloadable element suits that allow her to become the ComNet Fairy Corrector Yui who can fight Grosser's computer viruses.
Yui finds a hurt blue bird and then goes to investigate Medical Net's malfunction. Freeze has a not to pleasant encounter Rescue another Corrector program. Later Yui has a run-in with Freeze who destroys her com con. Then a strange man appears can he fix her con com? And will Freeze survive her next encounter with Rescue?
When Yui's dad asks her and some friends to test his company's latest VR, ""Marine Adventure Land,"" Yui is thrilled. But not all of Yui's friends are free, so double-dates (Yui and Shun, Haruna and Takashi) are arranged. The new game uses recordings of real whale songs to make people serene and happy... something Grosser's not about to let happen!
A computer-virus goes awry, causing Virus, Jaggy and Freeze to get transformed into mysterious entities. When the virus-infected Corrupters stubbornly refuse his help, War Wolf must make a difficult choice between deleting his comrades, or turning to Corrector Yui for help. Which will he chose you decide. But Warwolf prides himself on honor and loyalty can even an alliance with Corrector Yui be enough to save them and all of Com-net from being destroyed? Or will Warwolf be forced to Destroy his comrades?
Yui finds out that IR wasn't a dream after all! She trys sending a message to her friends, but with the help of IR, she sends it by Comnet Mail. At school, Yui is asked a question she does not know, ""The Mouth Is The Gateway To Disaster"". Freaking out, Yui is forced to go to the Virtual Comnet World, with the command ""Corrector Yui Enter!"" While in the virutal world, Yui discovers that one of Grosser's Cohorts, Virus has infected the mailmen, and the messages that everyone sends is turned into something nasty. When Yui returns to the real world, she finally has the answer to the question, which she types in her computer. The answer is correct. After that, Yui and her friends go to Haruna's Birthday Party.
A school-craze for fortune-telling develops into a destructive obsession. Who knew love advice could be so dangerous?
Yui and the other try to convince Eco that not all humans are bad. But at the same time Yui must also battle War Wolf. Who plans to burn the place to the ground! It turns out that Eco was the one who abducted all the people who littered in the nature park.