Admitably, this game looks terrible and shouldn't actually be as good as it is, but it exceeded even my limited expectations.
Story
If by chance you read japanese then congratulations you dont have to suffer through the horrible MTL translation this game has. Not a stab at the game at all, but for what's its worth this game does indeed have a story. Trying my best here to decipher the gibberish I went through.
Basically you play a guy that's stuck on a time loop, for a reason I couldn't tell. Evidentally something bad happened and youre dead, but the translations are so bad I cant confirm it. So for five days youre stuck on a train, with the same girl, and you decided for god know why, that youre going to fuck with this girl.
Every five days or so your game ends, your ending is based on your performance. Does this reach any satisfactory conclusion? Dont know, because the translation is shit. I read from some commenters that the girl is in fact trying to save your soul or some shit. Dont really care, if Im honest.
Gameplay
Here's where the game shines. You have the standard variety for games like this. Undress, molest, blowjobs, anal, etc. But the game doesn't let you do all that out of the blue. In fact attempting to undress the girl will immediately gameover your ass. Instead your task is to properly 'train' the girl and progressively get more options.
There's a limited amount of stuff you can do per day, and there's a meter that decides how much you can get away with. Spamming the same act doesn't work here, and the game does elegantly tell you if what youre doing isn't working, or if youre progressing. So for example, the girl doesn't take kisses very well at first but with enough head pats she gradually accepts your tongue. Its all very nicely done, narrated (or garbled) by the protagonist.
Unfortunately, the game is horrible at explaning how the game itself works. Getting an ending in this game doesn't get warped back on day 1 without progression. In fact what happens is you start over with your progression on the girl, roguelite style.
Also, bear in mind that this game is a patient sort, and there's no helpful meters that shows how much the girl is now trained in specific parts. So dont expect to fuck the girl until you've properly get her cumming at least twice, and that takes time. A word of advice: choose a body part (tits, crotch etc.) and stick with it. She'll be taking blowjobs by day 3-4 easily that way. Dont bother too much with the undressing, that'll come naturally.
Oh, and this game is properly point n click. There's no dragging anywhere or anything special. You choose and the girl reacts. Very nicely react I may add.
Progression
Alright, for all those who love these corruption themes, this game properly serves that niche. The poor girl will start off innocent, then slowly she'll get more receptive to your groping, and finally turns completely stockholm syndrome style. Supposedly to do this you'll have to get all the endings, which isn't trivial. So if youre into this kind of stuff, you'll get about 5 hours worth of your time getting this girl to beg for cock.
Pretty much one of the better games of its genre, but the chikan genre itself is fairly barren so if this scratches your itch then you owe it to yourself to at least try it. Recommended for those who can look past bad MTL for solid gameplay.