In Eromanga-sensei, Sagiri draws various pieces of (mostly-lewd) art in her guise as "Eromanga-sensei". For example, this one from episode 12:
Who is the real-life artist who draws the pictures that are portrayed as Sagiri's art in the anime?
There's a very consistent style to all of them, so I'm thinking it's just one person, but it doesn't look like Kanzaki Hiro's work (he's the character designer / artist for the Eromanga-sensei light novel).