I got caught up in it. A summoning to another world...

I'm an ordinary, average freelancer named Asahina Kotaro, and while I'm on my way back to my hometown during a long vacation I received, I encounter four students on their way home from school. As we're walking the same road, a black hole suddenly appears and sucks in the students. I end up getting sucked in too, and when I wake up, I've been summoned to another world. Moreover, they call me and the four students who were summoned with me "heroes." It seems I've gotten caught up in a hero summoning.