overall its a REALLY SLOW game but it has an interesting background plot.
The unlockable stuff from the main menu that is like "using bci to stimulate the brain to overcome ptsd by simulating situations" to make it "TOTALLY NOT THAT FORBIDDEN GENRE OF CHIKAN" basically, heh?
Uh, anyways, you can't do much until you grow her, but the force her into stuff grows her quickly. Otherwise it's generally a pattern of
"caress/rub thighs, kiss-lick ear-pat head>caress/rub thighs, grope breasts > caress/rub thighs, grope crotch > caress/rub thighs"
basically, thighs is like your free action in most situations. Once she lowers her arms straight you can lift/remove her clothes.
Sometimes you can just talk to her to lower her guard, but other times she'll hate everything and you have to rest (especially early on)
Trial and error, with a lot of grinding until you can do stuff, like generally the 4th or 5th time? It's not just B rank in her development, I was able to strip her in C, so it must be a specific development stat.