Inheritance! The Necklace of Death!

Insulting the Hokage dream in front of Naruto has consequences: a street duel, the Sannin versus the genin, settled with one finger to the forehead. But the boy charges the flick with a half-formed Rasengan that cracks the pavement — the Fourth's jutsu, in a child's hand — and Tsunade's contempt blinks. The wager forms around her grandmother's necklace, the First Hokage's crystal that legend says kills its unworthy wearers: master the Rasengan in one week and it's his. Both bet more than jewelry.