Haruka Makino stands as the eldest daughter in the Makino family, measuring 165 cm tall with figure measurements of 96-58-88. Her sisters are Akira, Fuyu, and Natsume. Following an off-screen traffic accident, their father Makino Ken'ichi undergoes a neurological shift, perceiving his daughters as sexual objects and targeting Haruka with predatory behavior.

Ken'ichi employs calculated manipulation against Haruka, such as offering deceptive back massages to lower her guard before assaulting her. Within the visual novel's narrative path, she confronts him about the ongoing exploitation, revealing her awareness of an aphrodisiac potion circulating among classmates and pleading for an end to the abuse due to emotional exhaustion. Ken'ichi praises her restraint before forcibly administering the confiscated potion to her and her sisters, inducing a state of hypersexuality in all four daughters.

Her experiences extend to public assaults in locations like parks and school settings as part of Ken'ichi's broader pattern of abuse. In one visual novel branching outcome, repeated non-consensual acts lead Haruka to a pregnancy ending where she becomes financially and emotionally dependent on Ken'ichi. Her unique "bad ending" within the visual novel involves her retaliating against Ken'ichi, but unlike her sisters' routes, he survives her actions.

In the OVA episode "Harvest," Haruka attempts to revert Ken'ichi to his pre-accident state, though her own desires complicate this goal. Their interactions escalate at her workplace into a mutually intense encounter, provoking jealousy among her sisters over her perceived monopolization of Ken'ichi's attention. This narrative explores her conflicted motives regarding whether she genuinely seeks his restoration or desires an exclusive connection. The OVA adaptation generally portrays the daughters as eventually willing participants, contrasting with the visual novel's emphasis on coercion and trauma.