I became a ghost in the horror game [Mystery Exploration Club ~Summer Vacation Nightmare~]. Give me back my body.
Translator’s summary:
Han Yoo-hee is an unlucky man who fell into the world of a horror game and became the tutorial boss.
Now, wanting to go back, he will guide the protagonist and her group through the game and achieve the ending, confronting many different monsters and finding more about the truth of this world.