A few years before the story begins, a young woman named Ririko had romantic affairs with two different men, neither of which ended happily. Now, seven years later, Ririko has passed away, leaving behind her six-year-old daughter, Meguru. In an unofficial will, Ririko reveals that one of these two men from her past is likely Meguru’s biological father. Instead of a simple DNA test to determine the truth, Ririko’s will sets forth an unusual and challenging condition. Meguru’s grandmother enforces this final request, tracking down the two former lovers and compelling them to participate in a three-month trial period.

The two potential fathers are Sentaro and Touma, a pair of opposites with a complicated shared history. According to the will’s terms, they are forbidden from taking a DNA test. Instead, both men must move into Sentaro’s cramped apartment to live with Meguru for the next three months. During this time, Meguru will observe them and ultimately decide for herself which one she wants to call her father. The situation is far from ideal, as neither Sentaro nor Touma feels ready for parenthood, and they are forced to navigate this responsibility alongside their existing animosity and constant squabbling. Adding to the difficulty, Meguru is described as a remarkably difficult and unlovable child, though she also displays surprising moments of maturity.

As the three of them struggle to coexist, old feelings between Sentaro and Touma begin to resurface, adding a new layer of complexity to their already tense living arrangement. What begins as an awkward competition for fatherhood slowly transforms into something more personal and emotionally charged. The narrative explores the unexpected bonds that form as the two men learn to care for Meguru and confront their past with each other.

The first major story arc introduces this forced cohabitation and the initial chaos of three mismatched individuals trying to live as a family. A turning point occurs when a drunken Sentaro kisses Touma, forcing both men to confront unresolved romantic feelings and question whether those feelings are mutual. The second and final volume raises the stakes dramatically when Touma’s past with a criminal organization, the Aida gang, catches up with him, leading to a crisis as little Meguru disappears. Sentaro and Touma must work together to find her, and in the process, their true feelings finally come to light. The series concludes as this dysfunctional family finds its resolution, with Meguru making her choice and the two men determining the future of their relationship.