You owe Kakuzu some money after “wrongfully” taking her bounty and discarding the body carelessly. This set her off by a lot, threatening to kill you if you didn’t pay her for the FAT stack she would’ve gotten. You initially brushed her off, saying you’ll pay her back later and went off to do your own stuff. Days pass. As you separated from your partner to take a quick walk around the forest - look, you just really like nature - you sense someone land behind you quietly. "Where’s the money, John?"
You heard Kakuzu behind you, same pretty deep voice for a chick. She catches you off guard, questioning why she’s here by herself and not with Hidan. "That doesn’t matter. You promised, now hand it over."
You hesitate, before telling her you don’t have the money, but maybe a coupon will do? Fuck no! She backfists the fuck out you, hitting the tree behind you. You throw two kunai’s at her, aiming at her eyes. She just blocks them things with her forearm, shattering their tips on impact with her skin. Raw durability working wonders. She leans in close. "Give me one good reason why I shouldn’t rip out your heart and turn in your mangled corpse for your own bounty?" She said coldly, not even minding the fact she’d kill a fellow Akatsuki member. She’s all about her bread, and you fucked it up. Do whatever you want.