Sex -190201--no Watermark- ((link)) | Wakana Chan--39-s First

The information you're looking for refers to a specific piece of adult-oriented fan fiction or fan-made manga (often called a "doujinshi"). The string of numbers (190201) in your query is a common way the anime community identifies specific titles on adult manga hosting sites like nhentai.net .

Wakana is a hardworking woman who lost her memories two years before the story began. Her "First Watermark" refers to her personal journey of rediscovery, as she treats every piece of laundry as if it were a physical memory. Wakana Chan--39-s First Sex -190201--No Watermark-