I think 'a knowing sister manhwa hentai' could imply a manga that involves a sister character in a somewhat risque or adult-themed situation. But without more information, it's hard to say for sure.
It usually features explicit and adult-oriented content related to a sister character with some form of awareness or knowledge. But such content is often not appropriate and may be against moral and legal norms.
Hentai involves pornographic and inappropriate content, so I can't recommend it. However, if you are interested in animations with good stories, I can recommend some like 'Spirited Away'. It has a wonderful story about a girl's adventure in a magical world filled with unique characters and moral lessons.
I'm not familiar with such content. Hentai manga often contains inappropriate or adult-oriented material that may not be suitable for general discussion.
The art style in these visual novels is often designed to be appealing in a non - sexual way. They use soft colors and cute character designs to convey the innocence of the sister - brother or sister - sister relationships. Take 'Sakura Spirit' for instance, the characters are drawn in a way that makes them look friendly and approachable.
This type of manga usually features adult and explicit content, often with themes related to sisters in different seasons. It's not suitable for general audiences.
The 'a new older sister hentai manga' is usually of a mature nature, often featuring explicit or suggestive content centered around the concept of a new older sister. It's important to note that this type of manga is restricted to certain age groups and may not be appropriate for general consumption.