This isn't really a review but more like stuff I want people thinking of reading this to know before starting since the tags and description don't really explain much.

The story starts with our MC who wakes up as another person in a webtoon he read. So basically a transmigration story (as you can see from the tags) but into a webtoon. The MC stumbles around in this new world before coming face to face with a villain (really just a monster, but all enemies of the magical girls are called... more>> 'villains' without much distinction) and, as per the title, has to transform (like Kamen Rider) or die to the monster.
His belt, which enables the transformation, is unlike the 'familiars' (IDK what to call them) of the magical girls since it forces him to do quests or else he will die. This forces him into uncomfortable situations like fighting the magical girls to live.
As for the harem tag, so far (in 27 chapters), it's more like a story where every other character besides the MC happens to be a girl rather than a full-on harem. That might change in the future but for now the harem aspect is negligible and in my opinion can be disregarded. Of course, the fact that the majority fo the cast is female is a given since this is a magical girl story.

There's more to the story than I've written but this is just to give you a better idea of what the story includes. You should definitely read it yourself to see if you like it. <<less

Kamen raider isekai, with harem. First of its kind that I ever saw, I'm pretty bad at putting reviews, but trust me this is good and if you like Kamen raider or magical you should try reading this, this has a pretty realistic internet culture, with how there are people that are positive and negative like the way they show down bad and h**ny people on the internet, the MC actually kill villains, and don't worry about this being like those magical girl show where it's all sunshine... more>> and rainbow, that's all from me and this is my very first ever review, so forgive me if it's a bad review cause I sucks at giving review, but I wanted to do it cause I like this novel with how it has Kamen raider <<less