This paper investigates the process and meaning of problem-based learning (PBL) that students may experience. The Project Cycle Management method was taught and utilised as an instrument of PBL at a Japanese women's college over a period of 5 years. The study closely examined what and how students learned in PBL from the perspectives of cognitive, social, and internal aspects. Despite the relative ignorance about the internal aspect of learners in previous research, the results of the study revealed that the internal aspect is inseparably linked with the other two aspects, and the three of them simultaneously undergo their own changes in the PBL process. That is, meaningful learning experiences seem to be no less importantly affected by the feelings or internal aspect of learners than by cognitive and social counterparts. Then, beyond knowledge building and skill acquirement, PBL may have contributed to broadening learners' perspectives and promoting their personal development. In this regard, PBL can be defined anew, from an angle different from that of previous research, as learning that can generate rich and varied emotions in learners concurrently as they face problems, enable them to acquire subject matter knowledge and relational skills through dialogue, and eventually guide them to the threshold of personal transformation.