Chu Si transmigrates into the body of the crown prince of the current dynasty, who is about to be deposed by the regent king, a man of a different surname. She hasn't even figured out how to save her life when the body she's transmigrated into suddenly starts developing at an alarming rate through puberty. The secondary sex characteristics are about to give her away.
"Your Highness, you smell so good."
That day, the regent king was supervising Chu Si as she reviewed memorials. His gaze casually flicked toward Chu Si's chest. Chu Si hurriedly crossed her arms over her chest and shook her head hard. "Don't look. I didn't sneak into the imperial kitchen to steal any buns today."
Theme: Stay alive and well.