Slice of life? Harem? AHAHAHAHAHAHAHAHAHA
Slice of limbs, guts, gizzards, legs, sanity, and insane amounts of blood maybe.
Oh boy, your imagination is far from what this novel is actually like.
It's pretty hard core. Especially the third arc. There's no way I could keep sanity in his shoes, absolutely no way.
This isn't your average "hero saves the day with his uber OP superpower so everyone can ride his dick" novel, thank god.
Nope, the author will make him suffer, suffer, suffer, suffer, suffer, then suffer more until he finally finds a way to make everything click together.
It's more like Okabe from Steins;gate, just 10x more sadistically written.