This is the story of an older brother who has been relentlessly targeted by his younger sibling’s friend. Youta wakes up one morning to find his younger brother’s friend, Daichi, sleeping naked beside him. Youta remembers running into Daichi at a drinking party the night before, but after drinking too much, he has no memory of what followed. The situation, however, strongly suggests that the two of them slept together. Youta is confused because he had always believed that Daichi and his brother Rui were mutually in love with each other. Consumed by guilt, Youta begins to avoid Daichi, but Daichi then confesses that it is Youta he has been in love with all along.

The story follows Youta, a young man who has completely misunderstood the romantic intentions of his brother’s friend, believing Daichi to be interested only in Rui. Daichi is the younger, attractive friend who has been patiently and strategically pursuing Youta. Rui is Youta’s younger brother, who complicates the relationship with his own brother complex and attempts to interfere with the budding romance. The narrative is set primarily in contemporary Japan, moving between the shared spaces of the brothers and the various locations where the characters interact, such as social drinking parties and their homes.

A notable narrative arc begins with the shocking, alcohol-induced morning after, which forces the central misunderstanding into the open. This is followed by Youta’s period of avoidance, driven by his mistaken guilt, and his eventual discovery of Daichi’s true feelings. After the initial misunderstanding is resolved, the pair become deeply affectionate. The story then focuses on the couple navigating the interference from Youta’s brother, whose affection for Youta becomes an obstacle that ultimately only strengthens the main pair’s bond. The final arc concludes with the couple deciding to live together, bringing the story to a happy and domestic conclusion.