Delicious in Dungeon, Vol. 4 by Ryoko Kui

The time has come! Showdown with the Red Dragon!!! After finally reaching the fifth floor, it's time for the adventurers to face their greatest challenge yet. They're putting their lives on to the line in a fight with a monster with crimson hide that turns away even the toughest steel and a fiery breath that turns even bones to ash. Can they save Laios's sister? ...And maybe just as importantly, can they eat dragon meat?!?

Publisher: ‎ Yen Press