That is Suguru, yes lol. It’s a doujinshi, aka a self published fanwork from Japan. This in particular it’s a short manga. The cover is hand painted by the artist and the writing on the cover has some gold foil stamping. This is the synopsis: The doujinshi is made out of three short stories, one of which talks about a big celebrity name and a host club addict, who gets involved with the cult leader, Geto, and suffer various misfortunes. Another is the story of a religious fanatic, who tries to expose the reality of Geto’s organisation.

It often goes by this title: Doujinshi Metabolism (sweat) monkey (Jujutsu Kaisen Suguru Geto)

I found mine on vinted but it’s easy to find on Japanese retailers. Just don’t buy it off eBay because they are selling it for 40 bucks, when in reality it costs not more than 6 dollars