Tears of joy well up in my eyes. It's a start.
Search results indicate that “Ane wa Yanmama Junyuuchuu 1” may be: ane wa yanmama junyuuchuu 1
is a niche adult manga work combining the Yanmama (delinquent mother) character trope with lactation and sibling incest themes. It is not a general-audience or academic topic but a specific product of Japan’s doujinshi adult market. If you encountered this title in a non-adult context, it was likely mislabeled or shared without proper content warnings. Tears of joy well up in my eyes