Ar'Kendrithyst - 259, 2/2

Suzuki, an adult programmer, suddenly notices that he’s been thrown into a different world while wearing a casual clothes at level 1. He gained high levels and treasures after using the 3 times use-disposable-magic, Meteor Shower, once. After that he intends to do different world “sightseeing tours”? He meets 3 beast girls, beautiful purple and black haired sisters, and an eccentric blonde haired elf girl along with various people during his trip. Although there are occasional fighting with demons and demon lords, this is a heartwarming fantasy story at heart.

Ham Dani, a normal student whose hobbies were to read novels.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

In 2120, a massive gateway that connects Earth with the Otherworld replaced the Aels boulder in central Australia. The Earth, representative of science, and the Otherworld, representative of magic, subsequently made contact and two wars broke out. Both wars inflicted enormous damage on both sides, eventually leading them to choose peace negotiations, and thereby marking a thirty-year era of peaceful exchanges between Earth and the Otherworld.Even though both sides chose to coexist peacefully, they each coveted the other's benefits. With the impending arrival of the third inter-world war, Earth's Otherworld combat General Staff Headquarters decided to secretly dispatch an advance team to the Otherworld to conduct pre-war reconnaissance.As a hybrid of Earthlings and Otherworld elves, Luoer, after secretly studying and training for over twenty years in Haiya Academy, which specializes in cultivating hybrids of Earthlings and Otherworld inhabitants, will soon lead his squad into an exciting adventure in the unknown Otherworld.Swords and magic? No, this is a world of guns and magic!