Recently stumbled across the fact that this Doujinshi exists, but it doesn't appear to be scanned/uploaded anywhere, and I can't buy it myself atm. Hoping someone else is interested enough and able to buy it 'cause it features one of my favorite characters.
https://www.melonbooks.co.jp/detail/detail.php?product_id=197206&adult_view=1
https://www.melonbooks.co.jp/detail/detail.php?product_id=197206&adult_view=1