"Oni Chichi Refresh" centers around a young man named Keisuke, who returns to his family home after a prolonged absence. Upon his arrival, he reconnects with his stepmother, Aya, and his younger stepsister, Rika. The household dynamic shifts as Keisuke begins to notice subtle changes in their behavior, particularly from Aya, who exhibits an increasingly affectionate and intimate demeanor toward him. This development creates tension within the family, as Keisuke struggles to navigate the blurred lines between familial bonds and romantic feelings.

The narrative explores the complexities of these relationships, delving into the emotional and psychological conflicts that arise. Keisuke’s interactions with Aya and Rika become more charged, with moments of vulnerability and confusion shaping the progression of the story. The series examines themes of desire, guilt, and the consequences of crossing boundaries within a family structure. The characters’ internal struggles are juxtaposed with their external actions, creating a layered portrayal of their evolving dynamics.

Keisuke’s character is portrayed as conflicted, torn between his sense of duty as a family member and his growing attraction to Aya. Aya, on the other hand, is depicted as both nurturing and enigmatic, her actions often leaving Keisuke questioning her intentions. Rika, though less central to the primary conflict, serves as a grounding presence, her innocence contrasting with the escalating tension between Keisuke and Aya. The interplay between these characters drives the narrative forward, highlighting the emotional stakes and moral dilemmas at the heart of the story.