Story starts with an absolute scum Marisa. She killed her sisters in their sleep so as to be the only pampered child. Her parents do all they can to let her take it easy, hunting all sorts of food for her, bringing her toys, massaging her feet when they're sore. And through it all, Marisa continues to act like a TOTAL shithead.
Everything changes when she stupidly accosts a human, who beats her up. Her parents come to her rescue, begging the human to spare their little one, which he promises to do if they agree to die. They waver at first, but hearing Marisa tell them to die for her hardens their determination, and the human kills them before kicking Marisa away.
Marisa's life changes after that. She never hunted before, her good food all brought to her by her skilled parents, and she was only tolerated by the clan because of her parents' reputation. She gets bullied by yukkuris who blame the useless scum for the deaths of the skilled parents, runs herself ragged and yet starves everyday, and becomes so dirty she fainted when she saw her reflection in water.
Then one day she comes back to find a black kitten in her house. She initially gets angry, but gets slapped around a little instead. The kitten brings her some insects to eat as apology, and Marisa utters her first 'happiness' in a LONG time. She declares the kitten her slave, and as a reward, names it Chibi (tiny).
Her life improves after that. She hunts together with Chibi, sleeping together for warmth when it's cold, and Chibi saves her from the bullies. They slowly begin to understand each other better (I was expecting the cat to kill her once it understood just what Marisa was saying). Despite calling Chibi her slave, Marisa starts to wonder if it's okay to be gentle with Chibi, whether it's okay to consider Chibi her slave. (UNBELIEVABLE... SHITHEAD IS CHANGING)
Then one rainy day, Chibi doesn't come back at its usual time. Worried, Marisa goes out in the rain, and finds Chibi hurt and bleeding. She finds out that another human did that, and brings Chibi back to their nest. Despite her attempts to lick Chibi back to health, the cat continues to weaken.
Marisa starts to think about what will happen if Chibi dies, and realizes all she has now is thanks to Chibi, and that she doesn't want Chibi to disappear. Wailing, she goes back out into the rain, screaming for anyone to help the cat. She even swears to do anything, cleaning, eating poop, becoming a slave.
Anon hears her, and talks to her only because she's a yukkuri out in the rain. When he realizes that Chibi is a cat, he asks one question. "This cat, what is she to you?" After some thought, Marisa answers. "Chibi is, Marisa's precious, family -ze..."
Anon chooses to believe her, and takes the cat away for help. Soaking wet, Marisa thinks back to everything that has happened, and finally understands that everything was her fault, being hated by other yukkuris, getting hurt by humans, losing her parents. All of that because she called a human scum.
"Thank you, Chibi..." Marisa's eyes start to close as she hears noises. "Chibi, take it easy..."
Later, Anon comes back to a home where Chibi is. She's obedient in all things except one, and that's to leave the cardboard box in the garden, which Anon picked up when he went back to search for Marisa. He drops off his groceries, and starts filling a food dish for Chibi. Then he hears some bouncing, and starts filling a second dish as he hears a joking voice declare the cardboard box as Marisa's easy place, and Chibi's joyful cry. Carrying both dishes, he heads for the garden.
END
Personally, I think there's a likely chance of Marisa and Chibi ending back out on the streets...
Is there any mention of Marisa also realizing how killing her sisters was a bad thing? because if not, I would had prefered remdeption through death and Chibi being the only one adopted, it would be kinda poetic if you think about it, Marisa killing her sis just to be pampered and served, and then dying to have someone else being taken care of as her final act of remdeption.