Daisuke Yamanaka is a 45-year-old member of the idol group Eternal Boys, having previously worked as a manager in the Management Department of Manpuku Entertainment Productions. His career began with early popularity as a model, but this initial success bred overconfidence that ultimately led to his expulsion from the entertainment industry due to behavioral issues. These professional setbacks resulted in significant personal struggles that altered the course of his life. During his lowest point, the former president of Manpuku Entertainment offered him a managerial role within the agency, an act of kindness for which Daisuke feels profound indebtedness. This gratitude fuels his unwavering loyalty and determination to support the company that gave him a second chance. As a person, Daisuke is inherently nurturing and supportive towards his fellow group members, balancing his background as a talent agent with his new position on stage. He is deeply invested in the survival and success of Manpuku Entertainment, and his primary motivation stems from a desire to honor the previous president's legacy and repay the faith that was placed in him. This dedication is so central to his character that the very concept for Eternal Boys originated directly from his experiences and his commitment to reviving the struggling agency. He joined the group as a performer not for personal glory, but as an active measure to contribute to the company's revival, proving that new beginnings are possible at any stage of life. Within the story, Daisuke serves as a key figure in the group, uniquely positioned as the member who was already working within the agency when Eternal Boys was formed. His role involves adapting to the physical and social demands of being a middle-aged idol while leveraging his managerial experience to help guide the group. His journey highlights a significant personal development, transitioning from a behind-the-scenes manager who had fallen from grace to a frontline performer and leader driven by loyalty and purpose. While specific combat or supernatural abilities are not associated with this version of the character, his notable strengths lie in his nurturing nature, his strategic understanding of the entertainment industry from his management days, and the emotional resilience he has built from overcoming past failures. The etymology of his name reflects aspects of his character, as Daisuke combines the characters for big or great with help, while Yamanaka means mountain and middle.