Remember "The 100 Girlfriends Who Really, Really, Really, Really, Really Love You," this is almost similar to that with a deserved horror plot.
First of all, if you read the MAL plot then I don't think I need to explain it further but it's not worth the time. The MC kinda drags the girls into a death game for his harem where the girls will be killing each other in order to survive. It's like forcing girls to play a part of a harem under the threat of a fate worse than death (an eternal loop of dying). And the main BOY is unaware of it. He has no idea about how the girls are handling this deadly game . They are forced to do all short of ecchi-harem stuffs(not everything) that they don't want and the BOY seems to enjoy it. The boy is not even the MC here. You'll find the reason very soon.
A death harem game is actually a new topic I am reading. But its not amusing. The author placed the black haired girl as the MC and the other girls are like her acquaintances(more like employees in a work). And the Boy is the plot device here. I have nothing more to say about the story.
The worst part is the finale. The finale is buullshiitt. First things first, the demon dies. But the girls who were forced to play the death game accepts the Harem. WTF?! Why? All the Male MC did was an apology. And the girls seemed to be pretty happy with that. I don't know what happened but I think the author did this intentionally.
But if you're really a light hearted RomCom-Harem Anime fan, then you should not watch it. But if you're tired of these Harem-OPMC bullshitts then you're welcome. Its really short to be amusing but Harem haters will enjoy it.
But the story is so much messed up that it does not deserve more than 4/10 in my opinion.