The participants in this study were 38 beginning-level English learners. Twelve of them were first-year English Communication majors and 26 were second-year International Social Studies majors at a university in the Tokyo area. A Digital Storytelling (DST) project was designed so that they would work cooperatively. Since positive interdependence and individual accountability are two essential principles of cooperative learning, the teacher paid careful attention to have them emerge in the activity. For example, students’ roles were divided in such a way that each of them would have a different piece of information, which facilitated positive interdependence. Also, the project was structured so that fulfillment of each member’s role/responsibility was essential (i.e., individual accountability was required) for successful completion of the project. A questionnaire with Likert scales was conducted before and after the project. In addition, a post-project questionnaire included an open-ended question. The Likert scale portion of the questionnaire measured the participants’ motivation for learning English. The question items used in this part were adapted from Hiromori (2006), who investigated EFL learners’ motivation with reference to the Self Determination Theory. The open-ended question was used to collect participants’ opinions towards the cooperative DST project. The results indicate that teamwork among learners was enhanced through the cooperative DST project, which in turn heightened their motivation to learn English. The Likert scale scores from the pre- and post-project tests were compared. The t-test results indicate that the participants’ motivation increased as a result of engaging in the project. Together with the participants’ comments collected in the post-project questionnaire, it can be concluded that teamwork among learners was enhanced through cooperative learning, which in turn heightened their motivation to learn English.