Game is pretty disappointing. Spoilers ahead. The sister-in-law is a slut before the game even begins. Turns out the MC's older brother doesn't satisfy her, so she's already at maximum degeneracy before the game starts; throughout the course of the game you find scenes with her gangbanging students at the school she's the nurse for, fucking her OBGYN, and fucking the clerk of some random costume store her husband happened to fall asleeep in. Since she starts at peak slut, there's not really any development over the game, just eight different scenes of her enjoying sex with the stereotypical fugly dudes. Nothing too exciting in terms of CG or sex content; one BJ picture plus a handful of different vaginal positions. No anal, no paizuri, no handjob, etc. You don't even get any MM+F CG's; just one-on-one pictures that reference other people nearby. It's a very disappointing lack of variety.
As for gameplay, the game has a solid premise but fails to deliver. The lack of meaningful upgrades for the the PC means that the gameplay gets stale a few minutes in. The exploration value is severely diminished due to only having a handful of scenes, most of which have near identical content AND most of which happen in one of a couple of plot relevant areas anyways. The MC isn't really a character; his reactions are identical regardless of his "purity" level. The ending is especially disappointing. Your reward for maximal completion is yet another boring, samey vaginal scene before the MC gets stabbed to death. Some sprite sex scenes to liven up exploration would've been a really nice touch.
Translation is nice though, props to Emerald_Gladiator. The untranslated bits are just stock "this door is locked" messages and the like.