@savagebj It's a fiance who doesn't want to marry her. Maybe it's an arranged marriage-to-be or there are other circumstances dictating it's hard for them to break up. The dude may have thought that if the woman is caught having sex with some stranger, it would be a solid reason to cancel the engagement.
@liquidsword Japan has a weird screwed up thing of never bringing attention to yourself. If you ever watched Sword Art, a girl killed a bank robber cause the gun fell over to her and she shot to protect herself, but everyone treats her like she's some massive piece of shit. If there was any proof she was naked in another room with another man regardless of context, reputation is broken, innocence ruined, blah blah. Granted if he's found he's fucked but if this went as it did, he would have gotten away.
I have two people I want to see get their bodies mutilated. One is that rapist and the second is the fiancee... just! Why? Why do something like that to a sweet girl like that? Forced marriage with only way out to ruin her?
One would think there would be some law against people reading others minds as invasion of privacy or something but it seems magic is public knowledge but not accepted as real...