How many endings are there?
I've gotten 4 different so far
Hm... Let me count. 2 Neutral Endings for the Lover and Slave Slut routes respectively, albeit those can be counted as one Ending. Then a Lover Slut Ending and a Slave Slut Ending. And then a Hidden Lover and Slave Slut Ending each. So 5 in total. Chances are you are missing the Hidden Lover Slut Ending.
Here a short explanation I copied in from when I explained it to someone else:
"You need the three special scenes. Bodyjob first with Clawjob cumming outside twice and Blowjob cumming outside once. Second and third scene will require other things, like to always have saved him or tried to save him from Digimon. Not to mention a large blue good bar. The third scene requires you to not go through the third Firewall after having found it. If all other requirements are met the third scene triggers and after having all three you will get the ending you want. ^^"