In the future world, humans have developed physiological perception sharing technology: after two people are bound, they can share each other's pain, fatigue, mood swings, body temperature and heartbeat in real time, but only voluntarily, and cannot be unbound within 72 hours after being bound. Unbinding requires confirmation from both parties at the same time.
The protagonist is bound to a complete stranger, and the shared perception cannot be blocked or deceived. All disguises are completely ineffective in the face of physical instinct.
