Chiharu Mitsuha lives together with her boyfriend's (masochist) nipples, which are constantly scratched by his little devilish girlfriend who loves them so much that they keep tingling.
[Agony! Nail scratching and nipple torture] The trigger was that I had a sensitive reaction to the nipple prank. Every day since then, he has been playing with the tip with his fingernails and making devilish expressions like "It's cute" and "It feels good". Every time you rub it, your body reacts twitchingly, your brain goes numb, and your precum overflows with pleasure. No matter where you are in the house, you will be irritated by the nipple fingernails, and you will be driven to the urge to ejaculate, and you will have sex to the limit of your patience. I'm already a super masochist whose nipples and dick are caressed from the time I wake up until I go to sleep and I can't stop tingling...