Yuusha Rin no Densetsu

When Souji Miyamoto, an ordinary college student, takes a test swing with a replica sword he bought on impulse, the last thing he expects is to be whisked away to another world. Yet that is precisely what happens. He arrives at the worst possible moment—right in the middle of a hero-summoning ritual being held in a certain kingdom—and before he can make sense of anything, he finds himself mistaken for the legendary Hero. His masquerade is short-lived, however. Through a strange turn of events, the princess uncovers the truth: he is nothing but a fake. Rather than expose him outright, she holds the secret over his head with a chilling warning—if anyone else learns that he is an impostor, he will be executed. With his life on the line, Souji is left with no choice but to take up the role he never asked for and set out on a journey to defeat the Demon King. But the road ahead proves anything but straightforward. Every member of the Hero's party turns out to be seriously eccentric, and each of them brings their own complications along for the ride...!