Randy is a young boy who devours comics and dreams of becoming a superhero. One day, he discovers a secret formula on the Internet that claims to provide an individual with superpowers. After assembling all the ingredients and technology required, he experiments with the process, but the whole thing goes terribly wrong. Somehow, by accident, his big sister Cecelia ends up with the very superpowers he'd been seeking for himself. And she has no idea what to do with them.

It falls to Randy to help her figure out what her powers are, select a costume, choose a superhero name, and teach her what it means to be a superhero. But while Randy and his sister are trying to figure things out and hide her new powers from their parents, the villain whose formula Randy inadvertently discovered is hunting for the thieves who stole his secret.

Written by The Legend Chuck Dixon, MY SISTER SUPREMA is a unique and charming superhero origin story.