Yū Ozaki is a tennis player and member of the boys' tennis club. He maintains a close friendship with Takayuki Todou and Takashi Chiba, often forming a trio with them. Their dynamic features frequent arguments, particularly between Ozaki and Todou, reflecting a vitriolic best buds relationship where conflicts coexist with strong camaraderie. Despite these clashes, they demonstrate effective teamwork, especially when paired for doubles matches in tennis competitions. Ozaki serves as captain of the boys' tennis team, indicating a leadership role among his peers. His characterization remains consistent as a supportive friend within the group, contributing to the interpersonal dynamics surrounding the central tennis narratives.