Tsukasa Kazuki[]
Yukana was bullied at her workplace. Because she was considered an outcast, she was "saved" by Tsukasa when he helped her up after she fell, and gave her bag back to her. This encounter causes her to become overly obsessed with him to the point that she became a yandere, which tarnishes Tsukasa's reputation and forces him to move away, but she finds him through the background of a candid social media photo.
Tsukasa's mother, Arisa Kazuki and Anzu Hoshino are all "horrible" in her eyes, as they try to tear "their love" apart.
Even after being hospitalized, she is fixated on Tsukasa and the only way to stop her is for Riri to wipe her memories. This causes her to lose years of memories and has no idea who Tsukasa is.
Anzu Hoshino[]
Yukana hires two thugs to attack Anzu, but was stopped by the arrival of Junta Hayami, Saki Takamine's older brother and Ryuya.
The harassment didn't stop there as Yukana later assaults Anzu (who left work) with a knife, but gets arrested thanks to Tsukasa Kazuki and Arisa Kazuki.