Koyomi's primary love interest and eventual wife. Initially introduced with a playful prank about parallel worlds, she becomes his steadfast partner. She collaborates with him at the research institute, survives traumatic identity-shifting events, and remains devoted to him despite numerical identity changes.
They form a lasting marital family despite repeated changes between parallel worlds.
The plot states that Koyomi and Kazune get married and remain together into old age.
Explore the full interactive character relationship map of To Every You I've Loved Before