Cross the Heir, Claim His Heart

One piece of perjured testimony wiped out the entire household of the general who guarded the northern border, and Luna Chung died with them. She wakes up alive again, some time before any of it, and decides the fastest way through is to steal the false testimony before it can be handed over. She has nearly got it when a man blocks her path in the dark. She stabs him, puts him on the ground, and takes his clothes so he cannot follow or raise an alarm. Afterwards she finds out he is Lord Henry, the heir of a princely house. To keep him from connecting the thief to her, she starts playing a sheltered, sickly girl who could not lift a sword if she tried. He does not go away. He turns up wherever she is and keeps setting small traps to see whether the frail young lady will slip.