Project-based learning (PjBL) has demonstrated its ability to improve a range of skills in students. However, some studies have reported that English teachers have difficulty activating interaction among all the participants, teachers and students, in a PjBL practice. No studies have empirically investigated how teachers can collaborate in PjBL and how students can engage in interactive learning activities. Therefore, this research demonstrates a PjBL practice led by the notion of value-centered team learning. A total of 19 teachers collaboratively implemented a year-long PjBL project with 73 high school students in Japan. The researcher used quantitative and qualitative questionnaires to collect data from students and teachers. Students' responses on their skill development and involvement in the project were statistically analyzed, and supplemented by qualitative analysis of their comments. Teachers' comments were inductively categorized into six categories from the perspective of what they learned in the project. The results show that value-centered team learning could contribute to success in creating a learning environment in which all the participants could learn much from each other through dynamic interaction. Therefore, this study suggests that English teachers should actively participate in PjBL by applying value-centered team learning.