Saikou Nando Meikyuu de Party ni Okizari ni Sareta S-Rank Kenshi, Hontou ni Mayoi Makutte Dare mo Shiranai Saishinbu e: Ore no Kan da to Tabun Kocchi ga Deguchi da to Omou

The swordsman, Jir, had just joined a well-known S-rank party when he finds himself stranded all alone in the hardest labyrinth. Normally, there's no way to survive such a situation other than to wait for rescue. Relying on nothing but his heroic sword skills, Jir decides to escape on his own! "Heh! You're all bark and no bite, Labyrinth!" he boldly declares. Due to his extremely poor sense of direction, he's completely unaware that he's headed towards the deepest level where the labyrinth boss awaits!!

(Source: Manga UP!)