This study examines the effects of exaggeration in advertisements of University, a type of service aimed at self-improvement. Claims such as “top 1% talent”, which are often used in university advertisements, can be judged as exaggerated advertisements using excessively ideal self-concept considering the level of students attending universities. In this case, it can contradict consumer’s own self-concept. Based on this reasoning, this study analyzes the effect of exaggerated advertising with actual and ideal self-congruence as mediating variables. Three survey-based experiments showed that the exaggerated self-concepts caused self-discrepancies with subjects, that self-discrepancies can negatively affect the attitude towards university. In particular, the effect of ideal self-congruence appeared in the form of reverse U, which negatively affects not only negative self-discrepancies but also positive self-discrepancies. Furthermore, the effects of the exaggerated self-concepts on the attitude towards university was significantly different between the case of adult subjects and high school student subjects.