Journal is a visual novel about a teenage girl and it takes place over the course of five days, from 8th October to 12th October 1987. She wakes up and discovers the journal she has been keeping is entirely blank. The game's story is about discovering how that has happened. The girl can be moved around as in a platformer between static screens, going left or right, or jumping. It is entirely narrative driven however and there are no platform elements. Instead, it consists entirely of meeting different people and going through the conversations. The game has a hand painted visual style with partial voice narration. The visuals are shown as drawings on a desk.
Each day starts at the house. Characters the girl meets include classmates at school, her parents and other people in the town. The players experiences the story through the girl, but she has secrets and parts of her history that are only revealed gradually through the conversations. Topics include her parents' divorce, dealing with cheating on tests and relationships at school, coping with her grandmother's passing and a major, repressed theme that eventually encompasses the entire game story. When striking up a conversation various topics can be chosen. There are multiple paths for the story through important decisions that influence feelings and relationships. A day ends with floating journal pages appear near the top of the screen, usually when all conversation options have been exhausted. Returning to the house, the girl's journal will be filled in with that day's events. Between each chapter there is a puppet theatre with a short slice of story about a carnival. Eventually the girl's story and the one about the carnival converge.
The game encourages replaying it to try different approaches and there is a secret ending that can only be discovered in the second playthrough.