Akuma-kun (ONA)

Mr. Satou is a company employee who is assigned to tutor Ichirou Matsushita, the son of his boss, in exchange for a promotion. However, Ichirou is not a typical student - he has a genius-level intellect and a dark agenda. Satou soon discovers that he is the second tutor in a row to be sent to Ichirou, and the previous tutor's disappearance is unexplained. Ichirou is revealed to be the one behind Satou's transformation into a lizard man, making him a servant, and is known as Akuma-kun, a master of black magic with the goal of opening a portal to hell and summoning powerful demons to aid him in his plans for world domination.