Technically there's !lightnovels@lemmy.my but as @kadu@lemmy.world pointed out it's probably a better idea at the start to dump everything into one community and then move as demand develops

I'd love to see light novels, webtoons, manhwa... But with the current number of users, I believe more generalist communities work better than several specialized ones

Feel free to join: !lightnovels@lemmy.ml . It's a bit lonely at the moment.