Purpose: This study was conducted to understand students' achievements in learning and to improve the overall curriculum of the first-year experience course. Design/methodology/approach: In this study, a series of questionnaire-based surveys were conducted on students enrolled in the Introductory Seminar for Policy Science, a mandatory first-year experience course offered in the first semester (from April to July) at a university in Japan. The studies were conducted in 2015 (n = 29), 2016 (n = 29) and 2017 (n = 31). Findings: Results revealed that, regardless of the year, students deepened their understanding of policy science and gained increased confidence to explain what group works and reports are throughout the semester. In addition, students' level of worry about life at the university decreased throughout the course in all three years. A stepwise multiple regression analysis (n = 84) revealed that those students who knew what policy science was (B = 0.271) and had the confidence to write their opinions in reports (B = 0.264) more likely answered that they knew what they wanted to study over four years at the university. Originality/value: This study revealed that the mandatory first-year experience course taught by the same instructor generated similar educational effects for different students in different years. The results elucidated the progressive effects of different components of the course, eliminating possibilities of any bias or specific characteristics of a single group of students.