This paper discusses whether technology-based performance tasks could become a mediator to communicating in English and enhance language learner engagement. The present study investigated how low-proficiency Japanese English-language learners could change their attitude toward communication in their target language by completing a performance task involving making and presenting a digital portfolio. Such students should need to mediate between themselves linguistically and contextually when completing a performance task for communication. The study adapted two types of questionnaires: open-ended questions about the performance task and four Likert-type questions about L2 learning motivation. Twenty-five students completed the questionnaires. The present study asked the students to answer each questionnaire twice, once at the end of the first semester and once at the end of the second semester. The data from the open-ended questions were analyzed qualitatively from a phenomenological research perspective, while the data collected from the four Likert-type questions were statistically analyzed. 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. However, the results of the Likert-type questionnaire suggested that such positive engagement would not necessarily lead to simultaneous English learning motivation. The results indicate that the task might become a “headstream” of directed motivational current (DMC) for the students.