This VN is an odd duck on my long list of recommended VNs.  While its existence as a time loop story is a trope, the way the game's story handles it is pretty interesting. 

I went ahead and revealed this as a loop story because you find it out so early on that hiding it as a spoiler is meaningless.  The game's story begins with the protagonist meeting (and helping out) Nodoka, one of the four heroines, and her confessing her love to him on the next day when she transfers into the class.  While he is at first somewhat bothered by this, he eventually falls for her, loves her... and then suddenly wakes up on the second day of the month, the day after he first met her.

Now, you will go through a lot of route loops before the game is over (you have to see all four heroine loops, plus a bunch of side loops, to get access to the endings), and a lot of these have seriously crazy outcomes.  The protagonist, being a young idiot, goes off and tests everything he can find (often to hilarious results), and his 'morality' tends to be rather fragile when it comes to having fun (in one loop he ends up gambling so hard he gets sold to an organ broker, lol).  To be honest, the journey through the non-heroine loops is probably the most attractive part of this VN.  The music is slightly below the average quality of the industry, as is the art (though that is comparison to the present day), but the game as a whole has a lot of laughs and good moments.

The protagonist, Minato, is essentially your average (slightly baka but not totally stupid) harem protagonist who is kind to everyone and as dense as the lead plating protecting a fission reactor's core.  Minato has solid reasons for being dense about the three heroines other than Nodoka (Nodoka being very open), based in his past relationships with the others (Inori being his abusive childhood friend, Korone being his little sister, and Yuuki being so friendly to everyone it is difficult for a harem protagonist to see it in her, lol).  That said, that is perhaps the most annoying part of his character, though it gets relieved over time.

Explaining the heroines to this game is counterproductive.  I'm not being mean, but if I were to start explaining the heroines, I would probably ruin the experience for you.  I really advise you not to read the character profiles (both because they are deliberately inaccurate and because forming your own impressions of the heroines is important to getting into this VN. 

There are five endings to this game.  One for each of the heroines and the true (harem, no H) ending.  The heroine endings are mostly kind of bittersweet, because there are solid reasons why things aren't going to end perfectly, but the true/harem ending is pretty hilarious.  Other than the true ending, I liked Korone's ending the best, both because I liked the outcome and because it was the happiest one other than the true one. 

Edit: Incidentally, Inori is probably the only case I've ever heard of where they handled the tsundere osananajimi realistically (rather than just using the sides as a contrast).