At thirty years old, Aizumi Asumi finds herself frustrated in a six-year relationship with a boyfriend who shows no intention of marrying her. On the night of their anniversary, a quarrel escalates and in a moment of heated impulse, she accidentally causes his death. When she wakes up the next morning, however, her supposedly dead boyfriend is sleeping peacefully beside her. Disoriented and confused, Asumi checks the date and discovers that time has rewound by one full month. In this reset timeline, her previously unemployed and freeloading boyfriend has been transformed into a hardworking salaryman. This sudden death triggers the beginning of a time loop, leaving Asumi to question whether this repetition is a divine second chance or something far more sinister.

The story follows Asumi as she navigates these recurring loops, each one resetting events after her boyfriend's death. The core conflict revolves around her desperate desire to escape the cycle and achieve a happy ending, symbolized by the goal of finally reaching the altar. The setting shifts between the mundane reality of a modern Japanese relationship and the surreal, claustrophobic experience of being trapped in time. As the loops progress, Asumi is forced to confront her own selfishness and the consequences of her actions.

In the notable final narrative arc, Asumi becomes caught in a fire set by a character named Takanari. She wakes up not in the recent past, but in the crumbling old apartment she lived in before the looping began, realizing everything has been reset to square one. Having experienced the terror of death, she deeply regrets her previous egotistical behavior and resolves to change her ways, determined to find happiness with the current version of Takanari. The story concludes with Asumi chasing her singular desire to be happier than anyone else, as the ultimate outcome of her repeated journeys through time unfolds.