The episode begins with Mikoto Yuzuki, the second eldest son of the Yuzuki family and a first-year student at Kaisei Junior High. He is portrayed as a calm and composed young man, admired by many girls and seen as mysterious by his male classmates. Mikoto has a younger brother, Minato, who is also in the first grade but is not his twin. Minato is described as childish and impulsive, which stands in stark contrast to Mikoto's demeanor.

The episode takes us back seven years, showing a young Minato struggling with the absence of his mother, who is hospitalized for childbirth. Even as a child, Mikoto tries to comfort his younger brother by drawing his favorite Power Ranger, leading to a heartwarming exchange of drawings.

The narrative then shifts to the birth of the youngest brother, Gakuto. Minato's initial dislike for another younger brother changes when he meets Gakuto. He quickly takes a liking to Gakuto and displays a similar brotherly complex as Mikoto.

With Gakuto's arrival, the dynamics within the Yuzuki family change. Minato, who was once very attached to Mikoto, now devotes all his attention to Gakuto. This shift leaves Mikoto feeling somewhat excluded and longing for the closeness he once shared with Minato.

Mikoto realizes that his jealousy is unfounded and that he should be happy about the strong bond between Minato and Gakuto. He accepts the change with a sense of enlightenment, understanding the joy and challenges that come with having a younger brother.