In many cases, visual novels are indeed rated by CERO. CERO provides a standardized rating system to determine the suitability of the content for different age groups based on various factors like violence, sexual content, and themes.
I'm not entirely sure specifically what the 'cero essence anime story' is about as it's not a widely known common title. It could be a very niche or self - created anime concept.
In many anime stories, Cero Essence could be acquired through interactions with powerful characters or by uncovering hidden locations. Sometimes, it requires solving complex puzzles or fulfilling certain conditions related to the plot.
Since we know so little about the 'cero essence anime story', it's difficult to say who the main characters might be. However, in most anime, there are characters who are central to the plot because of their relation to the main concept. So in this case, if the 'cero essence' is important, there might be a character who discovers it, or perhaps a character who is born with it. There could also be antagonists who want to use the 'cero essence' for their own malicious purposes.
One characteristic is the beautiful art style. Manhwa often has very detailed and aesthetically pleasing illustrations that enhance the romantic mood. For example, the way the characters' eyes are drawn can convey a lot of emotions. Another is the variety of themes. They can range from high school romances like in 'True Beauty' to more fantastical ones like in 'Orange Marmalade' where there are vampires.
Romance manhwa novels often have beautiful art styles. The characters are usually drawn in an aesthetically pleasing way, which enhances the romantic atmosphere. For example, the detailed expressions of the characters can show their love, shyness, or longing vividly.
Well, a common feature of a typical romance manhwa is the focus on the emotional journey of the couple. There's usually lots of cute moments, maybe some obstacles they have to overcome together to strengthen their bond. Also, the art style tends to be very appealing, making the characters look charming and the settings dreamy.