Retsumi Jugasaki[]
Retsumi is arguably Kareha's closest friend, with their friendship starting through the repeated times Retsumi, as an Empty near death, challenged Kareha to competitions. Throughout their interactions, Kareha maintains a playful façade to Retsumi, often enjoying teasing her for the slightest of matters.
Retsumi is among the few people that knows about her worsening condition in slowly transforming into an Empty. Moreover, it is through Kareha valuing her friendship with Retsumi that she was able to resist for so long. Ultimately, despite the dangers her transformation could cause to her friend, Kareha couldn't bring herself to push Retsumi away, wanting to be with her for as long as what was left possible.
Mizuha Banouin[]
During their time as humans, Kareha was very protective of her little sister and would often physically retaliate against anyone who would bully Mizuha. This protective nature would remain the same after both of them arrived in the Neighboring World as Quasi-Spirits, with Kareha often protecting Mizuha from enemies. According to Kareha, the Neighboring World is a miraculous world because Mizuha is alive here, which fulfilled her last dying prayer as a human for Mizuha to enjoy a meaningful life.
However, as she is slowly transforming into an Empty, Kareha virtually cuts off all contact with her little sister out of fear of losing her mind and accidentally hurting Mizuha.
White Queen[]
As Kareha confesses to Kurumi, she reveals that she is terrified of the White Queen and considers her to be a monster that no Quasi-Spirit should ever confront. Due to being infected by the awakening of love, Kareha's mind is slowly brainwashed into becoming one of the White Queen's fanatical followers. However, Kareha persisted in her resistance again the White Queen's control, ultimately choosing death rather than be forced to hurt her loved ones as one of the White Queen's subordinates.