This is a story idea that I have come up with. It's a JimxSuzanne story in which reincarnation is used. Originally, I was planning on having their death and rebirth occur as a result of a "black" Tower activating in Sector 5. Jeremie initiates a Return to the Past, but they are unaware of their teachers' deaths.
Before they became dead, Jim attempted to save Mrs. Hertz from a laser attack by a Crab, but he is mortally wounded and ends up dead. Mrs. Hertz also is shot by a Crab's laser, also ending up dead. Mr. Delmas permanently cancels the PE and science classes out of sadness, gives everyone a passing grade for each,makes the school week from Monday to Friday, and declares the Science Building, the Gym, and the Track as memorials for the now-passed teachers. Two "new students" appear (Jim and Mrs. Hertz reborn) the next few days later. The two retain their memories from their previous lives, and are dressed in different clothes.
Jim and Suzie are at first shocked, but they quickly readjust to their new lives as teens. William picks on Jim, not knowing who he is, and Jim retaliates by saying he is going to personally pound his face in (after William calls Jim a "loser"). Later that day, Ulrich teaches Jim the art of Pencak Silat while Yumi, Aelita, Odd, Jeremie, and Sissi take Suzie out on a shopping spree, not recalling who she is. When she does reveal her true identity, they don't care, as she is their friend now and not their teacher anymore. They learn about Lyoko and agree to help, as XANA is the thing responsible for causing their previous deaths in the first place.