EFL students often struggle with second language (L2) learning, particularly because they learn L2 out of context, which they find unmeaningful and demotivating. To provide a meaningful context for L2 learning and make learning more interesting, the present study utilized a customizable metaverse platform. First, we developed a scenario of a rose theft, and then based on that, we created a town in the metaverse, which offered a variety of multimodal language input and missions to solve the problem and identify the thief. The entire activity was developed grounded in constructivist language learning principles (e.g., contextualized, motivating, interactive, and task-based learning), thus, learners could explore, play, and learn in the playful constructivist space. Seventy-two Korean EFL students participated in the activity. The study employed a mixed method for more robust research. Quantitative data (the pre- and posttests and the post-survey) indicated the students had a great interest in the activity and the learning outcome increased. Qualitative data (the students' journals, the interviews with the teachers and the screen recordings) further evidenced the students' enjoyment of the activity. Particularly, the screen recordings showed how the students participated in the activity in the metaverse, collaboratively created an emergent narrative through interaction, and produced their own narrative to reach the answer. The study suggested pedagogical implications for using the metaverse for L2 learning based on the results of the study.