There’s the manga of it you can read. Sometimes manga is better than the adapted anime too. If you’re worrying about the fact that you won’t enjoy manga too much then trust me you’ll love reading manga more than watching anime. My opinion could be off too considering different people’s perspectives.
I know that there’s a manga and also a novel, that’s what the anime is based on. I even own some of the manga volumes. And yeah I like reading manga but no, I do not enjoy reading manga more than watching anime. That’s why I said that I definitely need the anime sequel. And apart from that, I don’t think that the manga is finished either since that’s the main reason why the anime doesn’t get a new season, afaik. Of course, I will read the manga and maybe even the novel someday. But I do always wait with reading a manga of a good anime because I do not want to get spoilered. For me, it’s much more exciting to see new scenes in anime than reading them in manga. I’m just that type.