https://www.dlsite.com/maniax/work/=/product_id/RJ01297493.html
https://www.dmm.co.jp/dc/doujin/-/detail/=/cid=d_480838

顔も性格も地味な紙魚川(しみかわ)はクラスでも目立たない存在だ
しかし彼女はその制服の下にとんでもない凶悪スケベボディを隠し持っていた…!
そんな紙魚川を’オカズ’に日夜オナニーに励む男子3人組
その名も『紙魚川さんを静かに愛でる会』
紙魚川を愛する彼らの妄想オナネタ発表会、ここに開幕!!
本編31ページ

[Synopsis]

Shimikawa, with a plain face and personality, is an inconspicuous presence in class.
However, under her uniform, she hides an incredibly lewd body...!
A group of three boys masturbate day and night using Shimikawa as their ''fun material''.
They call themselves the ''Society for Quietly Admiring Shimikawa-san''.
Here begins the presentation of their imaginary masturbation material for their love of Shimikawa!

Base +22, uberhaxwiz -6