Tomodachi no Okaa-san to Sefure ni Narimashita.

One day Hayata comes across writing scrawled on the wall in a public bathroom asking for a "naughty friend". Giving in to his curiosity, he sends a message and they agree to meet up. But to Hayata's surprise, the woman he encounters turns out to be his friend's mom.

(Source: Irodori Comics)

Notes:
- Released at Comic Market 98.
- A live-action AV adaptation (URE-064) was released on February 25th, 2021.