This one reminds me of the spicy Reimu-bitter Alice story. It comes in two parts, the anko number in the picture is of the 2nd one.
Title: To you, who's City-sect
Anon has abandoned his past life and is just working to make ends meet. When he sees a parent-child pair get fawned on by some schoolgirls, he decides to go to a petshop. At first he's put off by the prices, then he spots the 'to be disposed of' pile, filled with shitheads and scum. That's when he meets Alice. He notices that she doesn't jump like the others, probably to avoid accidentally crushing the koyukkuris with her. But while she doesn't insult him, she's cold towards him. (Tsundere)
After hearing that she would be gotten rid of soon, he decides to buy her. After asking what she normally likes to eat (bugs and flowers), he cooks her soba for her first meal. She is put off by the heat at first, but after he cools it down by blowing on it, she happily digs in. Later, while she's watching TV, he searches online for help in raising yukkuris. The first night they sleep together, and Alice whispers her thanks for his having chosen her. I
n the morning, he goes to buy yukkuri stuff for her, patting her head before he leaves. Tsundere Alice pretends she doesn't like it, but she's secretly happy. After buying a yukkuri house and food, he comes back to find his place in a mess. After he slaps her when she says she hasn't done wrong, a request not to move a book reveals the truth: Alice used to sleep with her parents and little sister, so she put the book there so as to allow her to climb onto the bed to sleep with Anon. The garbage bin was knocked over so she could do her business there and not dirty his room. He hugs her and apologizes, and she says that she wouldn't cry from something like that, even as he wipes her tears away. The yukkuri house is left unused.
Later, he feeds her some store-bought soba, but Alice notes that its different from the one she had before. He admits that the first one was made by his father and sent to him. That was the history he ran from because he couldn't live up to it. Alice tells him that she wants to try eating the soba he makes.
Despite having not done so in 3 years, he gets worked up about it, and when he finally finishes and serves Alice, she gives the same reaction of 'Happiness' that she did from his father's one. Finally understanding his father's words about seeing the expressions of those who eat the soba he makes, this encourages him to go back... he would become more 'city-sect' that way.
Anon isn't able to quit his job yet, he has lots of work to tie up. This restricts his time with Alice to breakfast and his coming home. But now he no longer sees her as a pet, but as his family. One day, he leaves as usual... not knowing Alice's farewell is the last time he'll ever hear her speak.
A Marisa and Patchouli trick their way into his place, and rape Alice. They kill the Koalices, leaving the Komarisas and Kopatchoulis alive, but with too many stalks, Alice dies, and those still on the stalks start to die too. That's when Anon comes back.
At first, he's shocked by the sight, not hearing Marisa and Patchy demanding that he save the children. But he comes to his senses and shuts them all in the yukkuri aquarium that was left unused, keeping the kos alive on the stalk. Later he mourns Alice... imagining a nonexistent future where she and him live happily together in his hometown.
He starts searching for abyuse videos and information, swearing not to give the yukkuris 'pain', but 'suffering' instead. When most of the kos on the stalk are born, he would begin.
When there's only one left on one stalk, he glues it to the stalk. It whines about wanting to be born, but with no new nutrients coming in, it starts to wither. He injects the stalk with salt water, and the Komarisa suffers and dies. All the while, the parents scream at him to save it.
When Marisa demands to know why he didn't help, he counters that they did the same when Alice died. Its answer makes murderous thoughts run through his mind, but he restrains himself and turns to the other four koyukkuris instead. For the koyukkuris, it would be pain, for the parents, it would be despair.
He releases one Kopatchouli, and the parents start jeering. Then he grabs it up again and sticks it with a thumbtack, and another, and another, and another... Only when the Marisa screams at him to stop instead of telling him to die does he stop.
"How dare you say that..."
He then continues to pierce the ko, taking care not to damage the paste core.
"Didn't Alice say 'stop' too?"
"Don't care about Alice-"
"Then I don't care about your lives either."
When it screams back, he puts down the ko, takes out Marisa and starts punching it, but stops himself from ending its life. When the Patchouli pleads with him to just spare the little ones, he verbally attacks them, and it can only admit its mistakes and apologize over and over. Then Patchouli tells him they should be even if he just lets the litte ones take it easy forever.
He snaps and revives the Marisa with orange juice, then shaking it before telling Patchouli if it wanted children so much, it should just refresh with Marisa. With children sucking out nutrients, Patchy begs for food, but Anon refuses. He recalls how there was yukkuri food scattered around the place on the day Alice died, but the yukkuris never fed her, so she died.
Anon kicks away Marisa as it tries to comfort its mate. Patchy begs its children to take it easy, but they refuse because they want to be born. Anon flicks them, increasing the demand for nutrients, and drain Patchy dry. Then the kos die as well. Marisa realizes its mate is dead and screams, then swears to protect its little ones.
"Just try it."
He grabs a Komarisa, and injects glue up its anyaru. Afterwards, he feeds the family, and after a bit of suspicion from the Marisa, it eats too. He wants them happy so they'll fully experience despair later. What he did reveals itself when they try to poo-poo, the first Komarisa is unable to do so. Marisa, realizing Anon did something, demands to know what.
He goads it to help its suffering child, but as time wears on, Marisa finally breaks down and begs for help. He tells it that since it never heeded Alice's begging, he won't either. The koyukkuri finally dies after attempting to vomit the old paste out, only wanting to do poo-poo.
He shuts the remaining three, the parent and a ko of each type, into the case, and Marisa just stares at the bodies of its dead family members. When it's time for their food, the kos beg their mother, who starts to cry when it remembers the promise it made. When it finally looks to Anon for food, he refuses.
Eventually he gives in, and takes Marisa's hat away. It doesn't seem to care, placing its children as the more important thing. That's when he starts pumping air into it, forcing out paste. Marisa tells her starving Kopatchouli to eat, but the Komarisa rams its sister to stop it.
Marisa opens its eyes to see Komarisa, whom Anon crushed because it didn't act the way he intended, which was to have both eat from their mother. He wonders why didn't it share this kindness with Alice.
He asks it if its children are important, and receives an affirmative response. Then he asks why did they do that to Alice, why couldn't they have children on their own. Marisa replies that there was too little food around, saying they couldn't gather enough. Eventually he finds out that Marisa was from the mountains, brought down into this city where the usual food couldn't be found.
He realizes just how hard it was for the pair, wanting to be parents. He comes to the realization about being city-sect... it's a harsh life where everyone, humans and yukkuri alive, are doing their best to survive. When he pulls out the pump, he feels like Alice just smiled at him.
Much later, he's having a drink with his father after the store has closed. Thanks to Alice, he's finally learned that what makes his soba delicious was who he was making it for, instead of his past attempts to imitate his father's.
One morning as he's preparing soba, an Alice calls out to him, begging for food. He feeds her, and she calls him city-sect. As she's eating, he thinks about asking her to be his pet yukkuri, but changes his mind.
The net has a lot of cases where pet yukkuris have died from forced refreshing by wild yukkuris. His case with Alice was one of those that is an example of a pet yukkuri protection scheme.
Anon decides that he would one day make soba just for Alice to eat.
From his country bumpkin self...
To her (you), who's city-sect.