Even with a Mana stat of 0.06, I'll become the strongest with just my skill

"There's not a monster a slingshot can't defeat" Yuu's father left him with a slingshot after saying that. With his proficiency with the slingshot, Kimura Yuu became "An F-rank with a 100% accuracy", and has become active in fighting low-grade monsters. However, with his mana at "0.06" and the lowest rank, the teammates he raids with often ridicules him. One day, a command window which writes "Target point reached, exclusive store has been unlocked" "Skill: Flint Finger has been given as a reward". With his skills levelling up, he started defeating high-grade monsters one-by-one, even with his 0.06 mana Will Yuu become the strongest Hunter with the slingshot his father left him