The influx of international students pursuing academic degrees in China in recent years has posed several challenges for educators who must cope with cultural and linguistic plurality. This qualitative dominant mixed-methods study explores how the engagement through partnership builds on and caters to cultural diversity. For one semester, seven international doctoral students of a course "Frontiers of the Learning Sciences" took on the role of course co-creators and discussion leaders. Classroom videos, student surveys, interviews, weekly reflection journals, and social media chatlogs were collected and analyzed. Results showed that engaging students as course co-creators was responsive to cultural diversity. Three interrelated factors emerged that defined the effectiveness of students' engagement within multicultural settings: language proficiency, academic ability, and personal attitude to the differences. Moreover, the study revealed four interconnected factors (time, challenge, competency, support) that should be considered in designing effective culturally responsive learning environments for international doctoral students.