When James P. Sullivan accidentally let a human named Riley Andersen into the Monster world, he has to return her to the human world and fast. But it's going to require some help from his friend, Mike Wazowski, a green, opinionated, feisty little one-eyed monster, and his girlfriend, Celia, a receptionist of the company in order to return the girl home.
Crossover - Monsters Inc. & Inside Out - Rated: K+ - English - Adventure/Humor - Chapters: 9 - Words: 26,959 - Reviews: 10 - Favs: 37 - Follows: 23 - Updated: 10/14/2021 - Published: 9/7/2021 - [Celia M., Mike W.] Sulley/James P. Sullivan, Riley - Complete