From Iskultrip Scans and Manga Abyss:

Maria Rose, a boy always mistaken as a girl, is burdened with debt after a strange event, and his sword, "Fake Consuming Inferno" is confiscated. At that time, Katari, a member of his clan, got a hold of some profitable information, but to obtain it, they have to go to an "Underground Raid", but things aren't as easy as it seems...

This is the story of love, friendship, and adventure of the beautiful "Cracker", Maria Rose.

Haruhiro awakens to darkness and amnesia, among a group of strangers who can only remember their own names…and nothing else. When they make it into the light, they discover Grimgar―a fantasy world that’s like something out of an RPG game. Without apparent skills or knowledge of their surroundings, Haruhiro and his newfound friends band together to form an adventuring party. Only by cooperating, using their wits, and learning new skills can they hope to survive in this dangerous land of monsters and magic.

(Source: Seven Seas Entertainment)