Yuuko Kouzuki teaches at Hakuryo High School as the homeroom instructor for Class 3-D. Displaying eccentric and manipulative traits, she frequently encourages Gouda Jouji's persistent romantic advances toward Akane Suzumiya for personal entertainment. This behavior reflects her pattern of inserting herself into students' private matters for amusement. She also sustains a competitive rivalry with fellow teacher Marimo Jinguuji, underscoring interpersonal tensions within the school environment.