you just need to lose to the 3 leader succubus enemies in their battles, if you have already beaten some of them they are in the recollection room aswell I think it unlocks when you beat them.
The first one (the loli) you just need to be defeated (without masochist mode).
The second you have to activate the masochist mode (Item > Action > masochist) and beg to her.
The third, same things than the second (best scene lol ) .
Yeah a lot of people are getting an alert because the translation is done by having a secondary program alter the main game, which is common enough that most security systems think its a virus. In fact mine was so sure it was a virus I had to download it like 5 times before I was fast enough to keep it from autodeleting
well all of the female characters seems to love the mc, it isn't just mindless sex either as they do grow as characters but don't expect to choose one girl to have them as gf. This is mostly a harem game. Their relationships are sweet tho so you can try it out.