This article describes a novel emergent emotion model for a context-aware Affective Mobile Guide with Attitude, a guide with emotions and personality that accompanies visitors touring an outdoor attraction. The interest lies in modelling the conditions to the emergence of emotions instead of prescripting emotions. The emotion model regulates the guide's emotions, behavior and beliefs, allowing the guide to adapt to its interaction environment flexibly. The guide adopts improvisational storytelling techniques taking into consideration the user's interests, its own interests, and its current memory activation in narration. It has emotional memory that stores its previous experiences allowing it to express its perspectives while narrating the stories. The guide's internal state is expressed through a 2-dimensional face where different facial features vary from one state to another along the arousal-pleasure emotional space. The guide exhibits potential in improving overall tour experience verified by a user evaluation.