There is no widely known mainstream or classical “long story” by that exact name. However, “Chona” is sometimes a recurring character name in indie or fan-made NTR works (especially from Japanese or Korean adult webcomics/dōjinshi circles), and “Ntrman” may refer to a creator or a stylistic tag.
It sounds like you’re referring to , a name often associated with NTR (Netorare) -themed adult stories or comics, typically found in certain online communities.
