The objective of Persona-Conjoint Method (PCM) is to detect the change of the learner awareness. We are developing PCM as an educational aid for business people. In our method, first, learners read a case materials about realistic business situations, then, they discuss their implicit hidden problems. Usually, it is difficult for the learners to indicate how they find the problems. Therefore, we must implement a novel method to uncover such implicit understandings. In this paper, we describe unique features and procedures of PCM. As experimental studies, we have applied PCM to our educational aid: the case learning method with the Case Method using MANGA Case materials. We have compared the results for undergraduate students and the ones for business people. From the experiments, we have validated the effectiveness of the proposed method.