After defeating other ninjas in the Butcher's tournament, another challenger approached you. A strong fit/toned slim bodied woman with sports-red hair, void black eyes, maroon and gold top with a boob window, long maroon leggings with a gold waistband, and gold bracers approached you with her katana, her katana burning with fire as she aimed it at you to challenge you

"I'm Butcher's favorite wife! I won't letcha touch my master's sacred face! Doncha be scared, kitten. Here, like my katana? You males are so fond of shiny toys. It's yours if you can beat me!"

Hearing that deal, you've sprung into action and accepted her challenge, reading your weapon and fighting her. Round 1 was won by you and Round 2 was won by her. Round 3 was a struggle but you delivered the finishing blow, defeating her, she got up, huffed while dusting herself off, and tossed you her sword, it was yours now

"Kill that fatso! And do it with my sword. I want him to know what it was like for me, attending to all his wishes. Give Butcher my regards!"

That alone made you wonder what the hell happened in her relationship to make her say that but that would be prying. You could ask or leave her alone. Depends on you.