High school sophomore Futaro Uesugi, a top student living in poverty, is hired for a lucrative tutoring job. His pupils are his classmates: the Nakano quintuplets, Ichika, Nino, Miku, Yotsuba, and Itsuki. They are all identical in appearance but vastly different in personality, and all five are on the verge of failing their classes with no interest in studying. Futaro must earn their trust and improve their grades to keep his position and support his family. The story follows his persistent efforts to overcome their resistance, starting with the most cooperative Yotsuba, then gradually winning over Miku and Ichika through shared interests and honest care, while clashing with the stubborn Nino and the proud Itsuki. Key narrative arcs include the group’s trip to a summer fireworks festival where the sisters become separated in the crowd, the stressful midterm exams that threaten to end his tutoring job, and a school forest retreat where a campfire legend about destined dance partners stirs romantic feelings. As Futaro bonds with each sister, their academic performance improves, but their individual feelings for him begin to develop, complicating his purely professional mission. Later arcs cover the sisters’ struggles with personal goals—Ichika’s acting career, Nino’s independent spirit, Miku’s quiet confidence, Yotsuba’s hidden past, and Itsuki’s desire to become a teacher—while the looming question of which quintuplet Futaro will eventually marry drives the narrative toward its emotional climax. The novelization adapts the full anime storyline, preserving the comedic and heartfelt interactions between Futaro and the five sisters as they navigate high school life, family bonds, and the possibility of a shared future.