My Weapon Is the Weakest but Apparently It Levels Up

A story about my rise from a humiliating NEET life to the strongest hero! The secret ingredient? The shattered and broken “weakest weapon?!” It turned out to be the only weapon in the world that levels up. Alongside the weakest weapon, this is the story of a ridiculed failure of a protagonist that ends up as a hero that saves the world!

Ore no Buki wa Saijaku Dakedo Level Up suru Rashii, 俺の武器は最弱だけどレベルアップするらしい