This paper discusses whether technology-based performance tasks could be a mediator to communicating in English and enhance language learner engagement. Through the research, this study investigated how low-proficiency Japanese English-language learners could change their attitude toward communicating in their target language by completing a performance task that involved making and presenting a digital portfolio. The students had to mediate between themselves linguistically and contextually when completing the performance task. The study adopted two types of questions in a questionnaire: one type involved a three-point Likert scale and the other included open-ended questions about the performance task. Thirty-three students in the first and twenty-eight in the second semester completed the questionnaire. The data from the open-ended questions were analyzed qualitatively from a phenomenological research perspective. The students’ comments on the task showed that they positively engaged in the performance task throughout the two semesters by reflecting on themselves as English learners, with some difficulty mediating themselves in L1 and L2.