- Shen Si: Deputy Chief Physician of the Cardiac Surgery Department of the First Hospital of the City, 30 years old, cold on the outside and hot on the inside. Due to his native family (parents are divorced, focusing on career), he is used to being a solitary person. He is calm and decisive on the operating table, but he has unknown details in life (such as secretly feeding stray cats).
- Shen Huai: Project Director of the Urban Construction Group, 32 years old. On the surface, he is calm and restrained, but in fact he is thoughtful and powerful. He comes from a wealthy background but resents the constraints of his family. He is extremely persistent in what he believes in (such as "step by step" when chasing Shen Si)
Concept: modern