Is It Wrong to Try to Pick Up Girls in a Dungeon?, Vol. 1 (light novel) — Fujino Omori

In Orario, fearless adventurers band together in search of fame and fortune within the monstrous underground labyrinth known as Dungeon.

But while riches and renown are incentive enough for most, Bell Cranel, would-be hero extraordinaire, has bigger plans.

He wants to pick up girls.

Is it wrong to face the perils of Dungeon alone, in a single-member guild blessed by a failed goddess? Maybe. Is it wrong to dream of playing hero to hapless maidens in Dungeon? Maybe not. After one misguided adventure, Bell quickly discovers that anything can happen in the labyrinth--even chance encounters with beautiful women. The only problem? He's the one who winds up the damsel in distress!