I agree so much with you. I didn’t mind this story at first but the more i continue reading it the more annoying it got. Truthfully what really annoyed me was the guy that’s a simp. His restless obsession with the girl that quite frankly wants nothing to do with him and is just a downright disgusting and horrible human that only cares about herself to the point where she was willing to have the mc get killed by the pig dude simply to save her senpai who was also as shitty as her made the story a mess. It just had no real plot and it seems like they were running around in circles with the story to the point that it became predictable.
if you come for a real plot, i should say you better read another series and don't waste your time here. rather than horror with suspense, this more like snuff polished by controversial stuffs like religion and sea pollution, but the execution is lacking in many aspects. other series from the same author; killing morph or pumpkin night imo have better story-telling, that atleast make sense. kikuchijima's plot is basically about a flock of freaks do freaky thing. at first, they were only islanders who living a very conventional way, until one family found this one eyed shaped stone and started to worship it, and the disaster begun
it started with very cliche plot point when some of college kids went on vacation until they found an island that has no specific info in google and even map. the stupidest part is, they decided to swam to that very island despite seeing a psycho beating up their friend until half dead lmao. then their ship got wrecked, and now they trapped in a deserted island with bunch of serial killers
unlike most series with serial killer that atleast got you symphatizing them, you only end up despising them because they got no point to kill people??? they're just possessed people who murder people in the name of 'religion'. so they have this one saint figure that they called "zanta maria" and she appeared to be just like virgin mary but with goat's head ((don't accuse me, that's just how it is drawn in manga))
it actually got a bit better when the flashback arcs getting into the room--when the islanders were blinded by money and they started to believe this one psycho, then the psycho made an agreement about disposal of pabric's waste and the island is no longer safe place to habituate--but, after that it getting round and round with amount of gore that i don't even understand if it even has correlation with the major plot
don't expect decent looking characters here because it has none lol. even the mc looks like beaten potatoes in a microwave. if you're not familiar with people using pig head or human skin as a mask, i don't think you'd be comfortable to read this. their characteristics even more nastier than how they look; there's one senpai ((who claimed he's popular)) and dated one girl from his club, but later found out that he been cheating his gf and fuck another members from that club. the incest army dad ((glad he got wrecked later lol)). the girl with scalpels glued fingers. and much more that would make you raise a brow if you haven't see much of weird looking characters
however if you're into gore and stuff like that, you'd probably enjoy this