Succubus Game ~Unbeknownst to my Girlfriend, I'm Pleasure Corrupted in My Dreams~

I have a cute and pure girlfriend. - You could say she's even out of my league. - However, since we started dating, we haven't advanced past the hand-holding stage, - and I'm at that age where I want to kiss and have lots of sex. - While I'm considering all this, suddenly SHE appeared... - In my dream, a woman calling herself a succubus. - This large-chested woman in revealing clothes makes me play a game. - "If you clear the game, you will awaken as usual. If you lose, you will be punished. - If you refuse, you will never awaken again." - Faced with this, I can only accept the conditions of the game...