"That’s why... as of today, you're out of the party." Forty years have passed since dungeons began appearing across the world. Keiichiro, a member of an elite S-rank adventurer party, is suddenly expelled by his childhood friend for being "too weak." His job, Trapper, is seen as useless—after all, it lacks any offensive abilities. Stripped of his future as an adventurer, Keiichiro sinks into despair—until he encounters a mysterious girl who grants him a unique skill. The skill, Arrow, shatters the limitations of a Trapper, transforming him into an unstoppable force. Determined to reclaim his place as an adventurer, Keiichiro embarks on a journey to become the strongest!