I Can Defeat an Old Dragon with My Bare Hands. It's Usually Like This, Isn't It?

Fil was picked up and raised by the [Great Sage], who once saved the world. Fil, who was raised as the grandchild of humanity's strongest great sage, inherited his talent, worked magic without chanting spells, and defeated dragons with his bare hands. However, one day, the great sage summoned his grandchild and told him, "Fil, I was silent so far, but you're a [female]."

Seriously!? By the way, what's a female? Fil's general knowledge didn't even contain gender. The great sage, who was concerned about his grandchild's future, decided to enroll Fil into the Royal Institute.