A brief description of the manga Death March Kara Hajimaru Isekai Kyousoukyoku:
The manga tells us about Suzuki Ichirou, a 29-year-old young programmer. His life changed dramatically when he entered an online game where his hero is a 15-year-old teenager named Sato. At first, our programmer thought it was a dream. But it was actually a reality. It was a virtual reality. He found out that his hero didn’t have superpowers. When enemies were attacking, his weapon was a special three-time meteor shower force that destroys lizards and gives him the ability to significantly increase his level. But with each new mission, in particular the return of the Demon King, is an obstacle to our hero.