A 22-year-old third-year university student named Tsuyoshi spends his days drifting between classes, his food delivery job, and the quiet solitude of his small apartment. His constant companion is a can of strong canned chuhai, a cheap and potent Japanese alcoholic beverage he uses to add some flavor to his otherwise mundane routine. This habit takes an unexpected and intimate turn when his aunt, Yui Koriyama, arrives for a surprise visit at the behest of his mother. What begins as an innocent family check-up quickly escalates after a few drinks, leading to a passionate encounter that blurs the lines between longing, desire, and morality. This initial transgression opens the door to a series of similarly illicit encounters, as Tsuyoshi finds himself entangled with a variety of married women, each connection forged and fueled over shared cans of chuhai.

The series adopts an omnibus or anthology format, with each of its eight short episodes focusing on a different woman and a distinct scenario. The setting is contemporary Japan, moving between Tsuyoshi's modest apartment, convenience stores, and the homes of the various women he meets. In one episode, a chance reunion at a convenience store reintroduces him to Ai Natsuno, his former high school junior who has transformed into a sun-kissed gyaru following her marriage. Despite her new look, she regresses to her old, spoiled mannerisms around Tsuyoshi, leading to another complicated affair. Another encounter involves an online drinking session with Miki Kanzaki, a college idol senior who is now married; as she gets drunk on chuhai, her behavior becomes increasingly uninhibited on screen. The narrative also ventures into more surreal territory, such as when Tsuyoshi meets a mysterious tanuki-faced beauty named Tamami Miyazawa who lives in a mansion, and even finds himself in a parallel universe where he must save a married dark elf named Simphis using skills granted by a "chuhai god".

Throughout these encounters, Tsuyoshi remains the common thread, a college student whose lazy life is repeatedly disrupted by these forbidden opportunities. Other notable women include Nozomi Kuji, a married woman who looks too young for her age and becomes his regular drinking buddy while venting about her husband's preferences, and Anastasia, the married Russian sister of his friend Joseph, whom he must care for after she gets drunk and mistakes him for her brother. The series concludes with an episode focused on Sari Kirihara, a charismatic barber in her late thirties with a husky voice and a past as a rebel. As a regular customer, Tsuyoshi accepts her invitation for home-cooked meals in the apartment above her shop, where her loneliness—stemming from an absent husband and grown children who have moved out—leads to a deepening physical and emotional connection with the much younger college student.