"7-nin no Santa Claus" centers around a unique premise involving seven individuals who are chosen to become Santa Claus figures, each tasked with delivering gifts to children around the world. The story begins with the sudden appearance of a mysterious organization that selects these seven people, who are ordinary individuals from various walks of life, to take on the role of Santa Claus. Each of the seven is given a specific region to cover, and they must work together to ensure that every child receives a gift on Christmas Eve.

The main characters include a diverse group of personalities, such as a struggling artist, a former athlete, a single parent, and a high school student, among others. Each character brings their own strengths, weaknesses, and personal struggles to the role, which adds depth to the narrative. As they prepare for their mission, they face numerous challenges, including logistical issues, personal doubts, and the pressure of living up to the expectations of being Santa Claus. The story explores themes of responsibility, teamwork, and the true meaning of giving, as the characters learn to overcome their individual limitations and work together for a common goal.

Throughout the series, the seven Santas encounter various obstacles, such as time constraints, resource shortages, and even conflicts within the group. The narrative also delves into the backstories of each character, revealing their motivations and the personal challenges they face outside of their Santa duties. These backstories provide context for their actions and decisions, making the characters more relatable and the story more engaging.

As Christmas Eve approaches, the tension builds, and the seven Santas must rely on their ingenuity, determination, and the support of one another to fulfill their mission. The climax of the story occurs on Christmas Eve, as the seven Santas race against time to deliver gifts to every child in their respective regions. The resolution of the story highlights the importance of cooperation, selflessness, and the spirit of Christmas, as the characters come to understand the impact of their actions on the lives of others.

"7-nin no Santa Claus" is a heartwarming and thought-provoking series that combines elements of fantasy, drama, and slice-of-life to create a compelling narrative. The story's focus on the personal growth of its characters and the challenges they face in their roles as Santa Claus figures makes it a unique and memorable addition to the genre.