Original Webtoon 72b5u
Official Translations:
Korean
After an accident when he was a child, Masato began hearing the voices of four people. They are known as “imaginary friends,” and each of them has a different personality.
One day, while playing a video game with them, he is summoned to the world of the game, “Heroes of Entria,” as a hero. Due to this, Masato has been separated from his imaginary friends and starts his adventure.
He is soon reunited with Masaki, one of his imaginary friends, and the two decide to continue their journey to find their other friends and go back home.
“Heroes of the future, we must drive the Demon King and his minions out of Entria, before Entria is filled with black mana…” Kuron’s message appeared before them. In it, it was written that Masato, a hero of the future generation, must save Entria.
The two divided friends have become undivided once again! A new sense of otherworldly fantasy begins!
50 Chapters (Complete)

At no point does the other world feel like a real place with real people. Everyone is dumb.
Shortly after arriving, the two main characters meet an annoying, incompetent girl far from town. Who is apparently adventuring in the woods in high heels and a short skirt. She screams and clutches the protagonist when she sees a mouse. How did she even make it this far from home? It's awful.
If there were an original source novel, perhaps it might have been better. But as presented, with this art, this is nonsense. You have to turn your brain off to endure it, but it's not worth the hassle.