This fucking logic, yes if she tells anyone we'll threaten to upload irrefutable evidence of us raping this girl on the internet, that's not counter intuitive at all.
@feeder in most countries the punishment for sexual assault/rape is lax, especially for minors. however, having something your identity online/face would be permanent, and they could easily obscure their faces in the recording --- meanwhile, that would've been linked to her professional and social life, which is a very important component of japanese society (to the extent people online often wear masks/obscure their actual identities to avoid sabotaging their social or professional status and place in society)