Ok, just for the heck of it, here's all the controls I've found:
A, S, D: Change quality (low, med, high)
Z, X: Change camera angle
C: Change the way the vagina is censored.
F: Add/remove socks
G: Add/remove glasses
M: Add/remove cat ears

This is how to win:
You have to do each of these things until you get the heart one step up.
(Except of course the ones you can't repeat.)
-Tickle her feet with hands
-Use hand, then tongue, on her mouth (move the head with hand first)
-Remove skirt and panties (with hand)
-Use the foam and shave
-Remove rest of the clothes (with hand)
-Use hand on her back
-Use hand, then tongue on her tits (move the hand from the way first)
-Use hand, then tongue, then brush on the vagina
-Spank
-Use the vibrator on the vagina, don't put it in, just float around
-Play around with the anal beads
-You get the dildo/cock. Use on vagina or mouth.
-ORGASMGET

Well, you can do those in any order you like. (Well of course you need to be
able to get the clothes removed and need to have the tools before you can
use them.)

EXTRA SPECIAL HOWTO: This is how to move the anal beads: Often they go in by
holding the button down and just nudging the bead closest to the vagina.
Sometimes not, then you have to use the plan B. (Also for removal.) Hold the
button while doing a circle motion in a way that the mouse goes over the anal
bead thingy+hand in the direction you want the beads to go, and when you move
the mouse back, don't touch it.

About the two options, I think they just have an effect on the story thing
before the actual game, as there is a skip button, and I didn't notice any
change on the game. Anyways, I did some searching on the words. My Japanese is
horrible, and most likely I have no idea what the words really mean in this
context, feel free to correct me. I have no idea what the actual story says.
I'm on Linux with Flash player 7 so I don't even see the text.

The first option: "goshujin sama": (n) (hon) your husband; her husband
Seems to be a bit more formal way of addressing someone else's husband. As
probably most people, I've seen it translated as "master".

The second option: "danna sama": (n) master (of house); husband (informal)
Seems to be a but more informal word for husband. I've also seen this word
used in the book Memoirs of a Geisha as the word for the (one) man who has a
steady relationship with a geisha and is her protector. (He can be also married
to someone else.) They also mentioned it means "husband". However that was a
story of a time 60 years ago, so it probably has nothing to do with this.

Now, the next mystery to solve is why on earth I used so much time on
something like this. *sigh*