There are people out there who don't know the first thing about writing, yet they are trying to write.

What's the first thing about writing? People will probably say or think of grammar and spelling, but I think otherwise. It's reading.

If you have not read literature, you should not be attempting to write literature. Not all readers are writers, but all writers are readers.

Reading manga and watching dramas and movies are not sufficient for writing. Those have plots, characters, etc., but they are ultimately different media. Pick up a book that's in English and read it. This is not me being an English supremacist; this is common sense. If you are writing in English, you need to familiarize yourself with English literature. Simply knowing English isn't enough. If it were, then every native speaker of English would be churning out New York Times bestsellers, and that's obviously not the case.

If the only books you have read are the Twilight books, that does not count. There are some people who basically read nothing but Twilight and call themselves bookworms. I facepalm at their existence. In case you think I'm singling out Twihards, I will also say that people who read nothing but Harry Potter cannot be called bookworms either.

Read a classic, read a scifi novel, read a mystery novel, read fantasy, read historical fiction, read a horror story if you have the stomach for it, read a variety of things.

When you're done reading (of course, you shouldn't stop altogether; I mean once you've gotten a good dose of literature), then you can venture into the realms of writing.