Fact: Asumi isn't in love with anyone. Asumi isn't looking for a girlfriend. Asumi has discovered the pleasures of lesbian sex and is now focused on having sex with as many attractive lasses as possible.
She isn't in love with Mai, she just wants to apologize to her.
She isn't in love with Nanao, she's just a friend.
She isn't in love with Whatshername-senpai, she's just a mentor.
She isn't in love with Serina or Ena or any of the brothel girls, they're just... yeah.
Asumi is an adult woman and wants to have consensual sex with lotsa other adult women because sex is great fun. And why wouldn't she? You don't need any other reason. All that stuff about romance and relationships is alien to her right now. Angry readers need to understand that this manga isn't a romcom. If anything, it's a sexcom.
Maybe one day Asumi will fall for some girl, but, seeing how she is right now, all I have to say is: don't expect it to happen anytime soon.