Extra To Protagonist - Chapter 38: Trip (1)

When Orion is mysteriously transmigrated into a primitive world where sex and other goods and services can be bartered for, he is determined to make the most of his second chance at life.

But as he delves deeper into this dangerous world filled with temptation and magic, Orion must use his wit, charm, and thirst for adventure to survive and make the most of his second chance at life.

Kusumi Chiharu gets a message one day that he has been selected as a Monster Tamer, and he is prompted to select his first partner. He thinks little of the message until he receives a giant package the following day. He assumes it’s the porn books he ordered, but the huge box ends up containing the unconscious body of a near-naked girl! She’s a ghoul named Zonmi, who intends to fight beside him as his partner.

However, it turns out that other hot girls at his mostly-male high school are also magical entities, and Zonmi may not be the only one who wants to fight by his side!

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.