Yusuke and Ayano are a young married couple trying to build a modest life together. After one year of marriage, their ambitions are limited to purchasing a second-hand home and perhaps affording a single child one day. They believe they have accepted their financial limits, content with a "just enough" family image they have envisioned for themselves. However, their seemingly ordinary lives hide a dark secret. The couple has accumulated a pile of money stored at their family altar, raising immediate questions about its origin. Their situation grows more unnerving with the presence of a stalker who commits bizarre and invasive acts, such as urinating through their mail slot.

The story is a neo-suspense thriller that explores how money drives people to madness, testing the very bonds of family. As the narrative unfolds, the couple's carefully maintained facade of contentment begins to crack under the weight of their secrets. The mysterious fortune becomes both a lifeline and a curse, attracting dangerous attention and forcing Yusuke and Ayano to confront how far they are willing to go to protect their vision of a family. The stalker's identity and motives remain a central point of tension, as his actions escalate.

The initial arc establishes the couple's modest dreams and the first hints of their unusual circumstances. The middle segments of the story delve into the escalating paranoia and suspense as the stalker's presence becomes more threatening and the source of the money is gradually revealed. The final arc brings the conflict to a head, forcing a resolution regarding the family's future and the price of their desperate plans. The series is set in contemporary Japan, primarily within the claustrophobic confines of the couple's home and the surrounding neighborhood, emphasizing the contrast between their normal exterior and the chaos within.