Song Shi'an transmigrates into the body of a struggling D-list actor buried in debt and becomes bound to a Supporting Character Acting System. By completing one hundred supporting character roles, he can earn a hundred billion in compensation and gain a new lease on life. Failure, however, means having his lifespan taken away. To survive, he takes on roles with limited screen time, playing everything from background extras, attendants, and students to elite lawyers. With his breathtaking looks and exceptional acting skills, he unexpectedly becomes a sensation. While juggling debt repayment, academic studies, scientific research, filming, and variety show appearances, he must also avoid the system's penalties for exceeding his allotted screen time. Through his breakout performances, he establishes himself in the entertainment industry and passes his first round of evaluation, only to face an entirely new challenge from the system.