From Renta! 6n3c5m

Taken advantage of by an unseen entity...
An arrogant problem student and his teacher who can see ghosts...
Pleasure that'll make anyone shudder! A horror-themed boys' love tale

Dead bodies found left and right, mysterious rumors, a town with a bewitching legend...
Reiji Hizuki is your ordinary, run-of-the-mill language arts teacher filling in for his predecessor who suddenly vanished one day... At least, he's supposed to be. Kyoichi Magaki is one of his problem students... Kyoichi tells Reiji he's pretty and wants to bang him, then proceeds to pounce. Reiji's fellow teacher follows with his own hunt as more and more strange events unfurl... What will happen to Reiji!? What should he do!? Be careful, Mr. Hizuki!

Alternate summary:

Strange rumors, mysterious legends, and suspicious corpses...

Hizuki Reiji is, by all s, a normal high school Japanese teacher, but he's thrust into the middle of a mystery when he moves to another town for a substitute teaching position. The woman he's replacing disappeared two weeks ago, and rumor has it that the problem child of her class, Magaki Kyoichi, was seen with a blood-stained knife the day before she vanished. The cops are on his trail, but what really happened to Sakuraba-sensei? And how are Hizuki and Magaki involved?