Zijie, a rebellious teenager, stumbles upon the unexpected perks of being mistaken for terminally ill. Intrigued by the attention and freedom, he chooses to play along, embracing a carefree “lying flat” lifestyle. His act soon draws the concern of Yezi, a straight-A classmate with a mysterious warmth. As Zijie's deception deepens, the lies spiral out of control. Just when he's on the verge of being exposed, a twist turns everything upside down—Yezi is the one truly battling a terminal illness. Bound by secrets and a ticking clock, the faker and the genuinely ill set off on a heartfelt mission: to check off each other’s bucket lists before time runs out.