[Nibiiro no Sora (Isuke Gratanity)] Hajime Numerigahara's Horny Investigation Report + Extras [Digital]

[Nibiiro no Sora (Isuke Gratanity)] Hajime Numerigahara's Horny Investigation Report + Extras [Digital]
[鈍色の空 (イスケ・グラタニティー)] 滑ヶ腹ハジメの淫乱な調査報告書＋α [DL版]

One of a selection of Isuke's doujinshi that used to be available on his Booth before being taken down for some reason, even though it's still up on DigiKet

Also contains a few sketch pages previews for a planned sequel that as far as I can tell never actually got released

I wish he did less shota garbage because as much as I like his art style I wouldn't be caught dead paying money for either of his two most recent standalone doujins (both of shitty gacha game TamaColle, a.k.a. "HouSamo for people who ONLY like the ugly Daichi Kouta children") or the most recent BOLD anthology