At the moment, the plot is escaping me;
But I do know that the pink hair girl featured in the title pic is the PC's sister.

Edit: you were right synce, thanks for correcting me.

Base +4

Step sister actually... game's about having sex with girls to cure them of a drug's side effects. Typical everyday situation in Japan.

Base +9, Krozam +8, Xcel +7, luffyq1 +6

An animation for this recently came out. I read the plot, all the girls involved drank some medicine with an unintended side effect, their breasts grew larger and they became incredibly horny. To devise a cure, the protagonist has to get them all pregnant.

Base +1

Newer version with more pictures can be found at /g/483724/dd2698c7c1/

Base +22