A high school boy moves into the Sunrise Residence apartment building and finds himself living alongside the thirteen Asahina brothers, gaining an unexpected vantage point on their extraordinary family life. Elsewhere, the manager of the idol group fortte, which involves the twelfth brother Futo, carries out her duties while being drawn into the brothers' orbit. A female high school student nurses a crush on the eleventh brother Yusuke and observes his interactions from the sidelines. The captain of the basketball team to which the ninth brother Subaru belongs contends with the team dynamics and Subaru's complicated home situation. These four ordinary people—each connected to one or more of the brothers in a supporting role—experience the everyday dramas, rivalries, and surprising warmth of the Asahina household from the outside, offering a fresh perspective on a family accustomed to being the center of attention. A fifth story steps away from the side characters to depict the day the youngest brother Yoru was born, revealing a foundational moment in the brothers' shared history. Together, these five original episodes expand the world of the Asahina family by focusing on the lives that revolve around them without being part of the immediate family.