Manga is Japanese. It has developed a huge fan base worldwide for its diverse characters, complex plots, and artistic expressions that are specific to Japanese creative traditions. In contrast, Chinese comics have their own names and styles that set them apart.
Well, there are several places. Some people recommend subscription-based services like BookLive or Kindle Unlimited Japan. Also, some manga authors have their own official websites where you might find their works in Japanese. Just make sure to have a reliable internet connection and a way to make payments if needed.
No, manga doesn't always have to be Japanese. These days, there are various international creators who produce content that follows the manga style, regardless of their nationality.
Yes, there are. Many popular Japanese manga have been translated into English and are available in various forms, such as physical books and digital editions.