Okay, so, played through it with an auto translator. Haven't played through all of it, but it's more date sim than a BF game, although there is definitely BF to be had.
When you first start out, you're declaring first what feels awkward for you:
Kisses
Anal
Blowjob
Nipple play(?)
Tickling
Second option is what do you like?
Kisses
Anal
Vaginal
Feet
Being Punished(One translator says this, the other says breasts. I'm not sure if it's one or both.)
Then the story begins. You find out about a sex fighting club. You get pit against a pink haired girl the translator seems to call Moonlight or Firefly. Bounces between the two. So then you fight. There's a few key options to pay attention to here.
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That should help things out. Now granted, I have yet to actually win a bout, but there is a way to at least bring it to draw. If you can last for fifteen turns, the fight will end either way. I think they also determine a winner after 15 turns, but it's hard to say with what I could get from the translator. You're also probably not going to win the first fight unless you're really, really lucky. As for the two unnamed options, I don't remember/can't find out what they do, but I believe they're both attacks as well.
Now for the other menu.
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There's also another option down at the bottom that brings up a calendar.
I'm not sure what the fist pump animation translates to, but it increases the third stat in the blue panel. Also, you can only save and masturbate at night. The menu in daytime and the menu at night time are different too. The alternate menu triggered by x is basically all stat reviews/skills/equip items. No consequences or time skips by pressing any of those.
The day menu is:
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The call option seems to be to learn more about the girls you've come across, and see how close you are to them. I haven't really tried anything with this one.
The go outside option takes you, well, outside. You can go to a fortune teller (first option. No idea what it does yet, really.) Go to shops (second option)
Wander aimlessly (I'm assuming this can trigger random events with other girls, but I haven't tried it as of yet.) and then the fourth option is Go back home.
With the shops, you have a choice of
Items
Clothing
Sex shop
Clothing actually will help boost your stats too, so I recommend getting some.
The best way I've found so far is just maintain a balance of all your blue stats to keep progressing well through the story, and the pink stats are all for sex fights. Oh another thing, if you don't sleep after losing a BF or another event, you stay at that low amount of HP, so definitely sleep after, or else you will not regain HP or SP.
That's all I've got so far. If I learn anything else that's important, I'll be sure to let you know.