Hmm, ngl, I cant enjoy the fluffy parts as things are now.
Im constantly remembering that sus part in the first chapter with the tutor of the blachaired girl (possible crush or groomer, we don't know).
Also, because of the initial scene, we know they are going to try have sex, possibly on the seventh day, but maybe before.
Im afraid the dark haired girl is maybe trying to lead the gyaru into sex with no feelings and "using" for pleasure her as a way to forget/normalize a possible sexual abuse from her tutor.