Unknown Heroes

When Akihiko Bushida's childhood friend, Ryu Kazama, goes missing, he sets out to find him. However, his search ends up leading to his own death and he wakes up in the world of Seldain as a Hero with magical abilities. Now Akihiko must team up with new and old friends to help take down The Demon King so he can get back home.

You can read Unknown Heroes here: https://www.webtoons.com/en/challenge/unknown-heroes/list?title_no=857790