It's a collection of different stories where the first story its a guy reluctantly lets a runaway girl sleep at his place and then they have sex.
Later another girl show up and its reveal she the first girl its from a rich family and she 's her bodyguard and want her go back to her family.
Rich girl said no because they're in love (she in love the dude not so much) and have sex in front of the bodyguard to prove it.
It work and she back off.
Oh, and the bodyguard girl complain to the author during the afterword part of the manga about not getting fucked so he calls a bunch of character from the other stories to gang bang her.
Later another girl show up and its reveal she the first girl its from a rich family and she 's her bodyguard and want her go back to her family.
Rich girl said no because they're in love (she in love the dude not so much) and have sex in front of the bodyguard to prove it.
It work and she back off.
Oh, and the bodyguard girl complain to the author during the afterword part of the manga about not getting fucked so he calls a bunch of character from the other stories to gang bang her.