Shionokami
Haven't started reading yet but I didn't know where to point this out. Your synopsis has a lot of grammatical errors, mostly run-on sentences. I rewrote it below, you can copy-paste it or use it as a reference to fix your synopsis: 40 years ago, our world believed that magic was merely a myth, a fiction, and nothing more. But that all changed when it was recently revealed that magic truly does exist to the public. To that end, a place was created, a place where magic can be studied and taught. And that place is Takamagahara Island, the home of a certain Kurokami Tatsuro: a young man who just wants to live his days with nary a trouble. That is until he has a fateful encounter one day, an encounter that would change not only his life but the entire world ...
Your right. But I feel Grammarly exaggerates as well and their premium is so expensive that one can't consider though it is very good and I do recommend it. Yet, they should try understanding that youths are out there who write and they need to reduce their amount and reconsider because we aren't into regular business to pay throughout
Drakonous:Google doc has the most basic version of a spell checker. It'll point out inconsistencies but I found that Grammarly points it out a lot better and even gives suggestions on how to fix it while explaining exactly why it's wrong grammatically speaking. In that essence, it's way better than Google docs