"Dōsei" is a romance social simulation game in which the player assumes the role of Masaki Yamada. Much of its gameplay is spent on reading the story's narrative and dialogue. "Dōsei" follows a branching plot line with multiple endings, and depending on the decisions that the player makes during the game, the plot will progress in a specific direction. Throughout gameplay, the player is given multiple options to choose from, and text progression pauses at these points until a choice is made. To view all plot lines in their entirety, the player will have to replay the game multiple times and choose different choices to further the plot to an alternate direction.