Oh wow that was fast. Thanks for translating the chapter and uploading it early!
Omg the two know each other! I am guessing they went to the same high school but Momoka's sister doesn't seem that excited in seeing her again. I am now most curious though in what is going on with the names. There is so much I don't know yet and can't wait to find out about lol.
Also death by boob to the face? I would just find it impressive that someone could deliver enough force with their breasts to snap someone's neck.
Oh ffs.... Well at least we now know why she took the false name of Riko. I can already guess how it goes. Aoi was probably in love with Riko but didn't want to tell her how she felt and was conflicted about her feelings towards Riko. Hench the part about being frail according to the owner in chapter 14 for rejecting her own sexuality. Or she got rejected by the younger sister. Heh rejected two times would be hilarious though. Well we'll see.