This narrative case study examines the identity development of two mixed-heritage (Korean/White and Korean/Japanese) university students in relation to Korean as a heritage language (HL) in New Zealand. The narratives of the two participants (Mia and Hannah) revealed that they grew up with different levels of exposure to the HL, which impacted their HL proficiency, and experienced different struggles with identity construction. While Mia's White appearance helped her explore multiple ethnic/cultural identities, Hannah was deemed completely non-White by White New Zealanders, assigned a minority "Asian" identity, and subjected to racial discrimination. The dominant group's confusion about intra-race mixedness and perceptions of Hannah as non-mixed complicated her situation. Hannah had little access to a majority heritage (New Zealander) identity, but also found her specific heritage identities occluded by an imposed single ("Asian") identity. Nonetheless, on entering university both participants showed a strong desire to embrace their Koreanness through HL education or socialization with coethnic peers. HL learning played a crucial role in their construction of mixed-heritage identity; for Mia, the HL was valuable social capital, while for Hannah, the HL was a means of claiming her ethnic identity. This study highlights the complexity and plurality of mixed-heritage identities and offers implications for educators.