Academy Yageme Binguihaessda.

He left a really negative review on a hentai game... Only to wake up as the main character! To make things worse, he will be killed by the god of games unless he gets all 6 girls in the game to fall for him!
"Damn it... Fine, I'll do whatever it takes to get all the girls!"
(Source: DAYcomics)
Note: Chapter count includes an epilogue.