Fraiser's manga / #Psycho Yaoi(1)

Problematic premise, but yah, I liked it. So... Classmate blackmails our main character over him showing up to school with no underwear. Classmate has our MC "do whatever he says". Coercive, sexual blackmail encounters ensue over the course of about a week. Or Creepy classmate uses blackmail as a way to fuck the Senpai he likes. I did like this, but it's nonsensical. Also, this author likes rape too much....