DanMachi: Is It Wrong to Try to Pick Up Girls in a Dungeon?: (Argonaut) Wanting To Be A Hero

SINOPSIS

For an adventurer to level up, and truly get stronger, he has to go on an adventure. Bell travels down to the lowest of the upper floors of the dungeon, where he encounters a minotaur with a giant sword. Lili is badly injured, and Bell is unable to leave her behind. Aiz arrives again to save him, but he waves her off...