Hazure Skill "Mapping" wo Te ni Shita Shounen wa Saikyou Party to Dungeon ni Idomu (Mephisto)

Note Athlon was really looking forward to becoming an adventurer with his best friend (and crush) Miya. That is, until he drew Mapping—a rare skill with practically no purpose. In other words, it's trash. This kicks off a vicious spiral for Note, who plummets further and further into the depths of self-loathing despair when Miya leaves him. He now spends his days drinking away his earnings, wondering how things might have been different if only he’d pulled a better skill...

But little does he know his trash-tier skill is about to score him an invite to a top-tier adventuring party! Note's now determined to find his way through life—and a dungeon!—in order to make something of himself.

(Source: J-Novel Club)