Siblings Wanted

""My parents won't buy me a dog."

"How did you ask them?"

"I asked, 'Mum and Dad, can I have a dog?'"

"That's the wrong way. You have to ask, 'Mum and Dad, can I have a baby brother?""

Siblings. Lots of us have 'em. Lots of us don't. The latter situation is often quite common in fiction, leading to a lot of only children running around.

But some fictional only kids (especially younger ones) are not happy with the situation. Maybe they're lonely because they have no one to play with. Maybe they're frustrated because they have no one to push around. Maybe they just see a lot of other kids with siblings in real life and are just jealous. Whatever way, they know what they really want: A younger sibling. And they aren't afraid to ask their parents for one.

Their parents are generally less thrilled about this, because even if they also want another child, they're not keen on telling their kid where said baby is going to come from.

Frequently, kids will express a desire for a sibling the same gender as them: Girls generally want little sisters, and boys typically want little brothers. But the opposite situation isn't unknown: Sometimes boys want little sisters in an attempt to purposefully invoke Big Brother Instinct. Similarly, sometimes tomboyish girls will want brothers... and not-so-tomboyish ones want living dolls.

In works with a fantastic bent, this may be a cue for a younger sibling to suddenly come into the picture through supernatural or superscience-y means. In less-fantastic works, it's often up in the air whether the kid gets their sibling or not. Nor is there any guarantee that, should they get their wish, they and their new sibling will get along the way the older one dreamed.

Compare I Want Grandkids (for when it's the parents' parents doing the pushing). This is also Truth in Television, which is probably why it shows up often enough.

Anime and Manga

 * Chocotto Sister is about a boy who always wanted to be an older brother, but who never got a younger sibling... until one day, in his college years, Santa Claus gives him a little sister for Christmas.
 * In Nanoha the Movie First, it is revealed that Alicia Testarossa always wanted a little sister (which is exactly what Fate is to her), as Presea remembers.

Film

 * In the film The Hunt for Red October, Jack Ryan tells his CIA boss that his daughter ("a very precocious five") asked him and his wife to "buy her a baby brother" and settled for them buying one for Stanley (her teddy bear) instead. At the close of the film, Ryan is shown sleeping on his flight home with a teddy bear in the next seat.

Literature

 * In the Dresden Files short story It's My Birthday Too Harry Dresden reveals that he wished for a brother when he was a child in the orphanage after his father's death. Ironically (and heartwarmingly), the person he's telling this story too is

Newspaper Comics

 * Calvin once tells his mother he wishes he had a little brother. "You want a new friend to play with?" "No, I just want somebody small I could beat up." The next panel is Calvin's dad at work telling his wife they'll talk about that operation later.
 * Subverted later when Calvin's Mom is sick, Hobbes suggests she might be pregnant, and Calvin panics.

Web Comics

 * In Drowtales, it's considered good luck to have twins or a similar - age sibling. As a result, the Sharen clan has the practice of a "protector twin" (adopting - or buying - a child, usually from a servant family) to give their own children a chance to have a same - age sibling. Unfortunately, this often results in sibling rivalry, ending with the death of the protector twin at the hands of the former child, or (less often) vice versa.

Web Original

 * Chakona Space has examples of Chakat cubs asking their parents to get busy giving them a little sister.

Western Animation

 * One episode of The Adventures of Jimmy Neutron involved the title character asking his parents for a little brother. Since they politely declined, he used his mad science to make a robotic little brother named Brobot. Brobot didn't stick around on Earth, but did become a minor recurring character.
 * One episode of Rugrats involved Tommy really wanting a little brother. He then thinks that a bird's egg is his little brother Milton. The egg was just a baby bird, but he did get a real little brother named Dil after The Revival.
 * One short on the What a Cartoon Show involved a little girl who kept tons of animals in her own personal "zoo," because her parents never caved in her desire for a little brother. Doesn't stop her from asking about it incessantly, though.
 * Littlefoot in at least one of the The Land Before Time sequels has shown interest in wanting a sibling. It doesn't help that he's one of the only main characters in the entire series (except for Chomper) to be an only child.
 * Once on The Simpsons Bart asked for a little brother but his parents said no, so he went to an orphanage to adopt one.
 * Zig Zagged in the Family Guy episode "Emission Impossible": first is inverted when Stewie hears that Peter and Lois want another kid, and he tries to sabotage any of their attempt at having sex. After meeting one of his possible future siblings inside Peter's testicles (It Makes Sense in Context), he's eager to have a younger sibling. However, he later made up his mind again.

Video Games

 * Many of the "rival children" in Harvest Moon: Animal Parade express a desire for younger siblings, but the two who fit the trope most closely are Lucy and Dakota. Lucy asked her parents, and they agreed, but never have any luck having a second because Status Quo Is God. Dakota, meanwhile, went all the way to the Harvest King to ask for a little sister, but he told her there was nothing he could do unless her parents started getting along first.