This project aimed to evaluate the effectiveness of an academic success center at a Japanese public university, in terms of the reciprocal learning that took place during academic writing and reading tutorials and the academic achievement of tutees. Using a multi-method design, the researchers analyzed feedback data from tutors and tutees, and Grade Point Averages (GPA) of tutees and non-users. Questionnaire feedback from both peer tutors and tutees was analysed to understand what learning took place during sessions. The results from one semester of data collection and examples of learning shared by tutors and tutees on the feedback forms are explained. Additionally, a one-way ANOVA was conducted to compare GPA at the beginning and end of the semester, along with changes in GPA of tutees and non-users. This paper aims to contribute to better understanding the role for academic success centers, especially in relation to the growing context of English-medium instruction.