Naori Shida is a reserved college student who loves mixing cocktails but has no one to share them with. Her life changes after a mixer where she meets the fashionable and outgoing Hinata Ibuki. Thinking Hinata has simply had too much to drink, Naori takes her home. Once there, Hinata asks for another beverage, and when Naori obliges, a pair of horns sprout from Hinata's head. Hinata reveals she is a descendant of the legendary ogre Shuten-douji. Cursed to survive only on alcohol, she has a critical weakness: an ogre can only consume liquor that is willingly offered by a human. As someone who both loves making drinks and is human, Naori becomes the perfect caretaker. To protect Hinata's secret, Naori agrees to serve as her personal bartender, and the two begin living together.

The story unfolds in a contemporary Japanese setting, following the daily lives of this unlikely pair. The central dynamic explores an ironic power balance. Hinata is a social butterfly and a supernatural being with immense power, yet she is completely dependent on the timid and physically weak Naori for survival. Conversely, Naori is a lonely human who finds a sense of purpose and courage through her role, gaining a companion who genuinely appreciates her niche hobby of mixology. Their relationship deepens as they navigate cohabitation, with Naori crafting various cocktails and Hinata reacting with visible changes like growing horns, offering a recurring visual cue for their connection.

Several narrative arcs define the series. Early chapters focus on establishing the rules of this world, such as the fact that ogres cannot feed themselves and must rely on human offerings. As the story progresses, it moves beyond simple slice-of-life moments to subvert initial expectations. The quiet Naori frequently displays unexpected bravery to protect Hinata, while the seemingly invincible Hinata reveals personal insecurities. The plot becomes more ambitious over time, introducing other characters and supernatural elements that expand the world beyond the pair's apartment. While some critics note that new supporting characters are introduced rapidly without immediate deep exploration, this shift indicates a growing, more complex storyline involving the history and families of the ogres.