Children Raise You

"If you're a man, you may feel unready or unwilling to have a baby, in which case you're just a party pooper. You should rise to the occasion and improve yourself if necessary."

- Bright Lights Film Journal

All the fun of unplanned parenthood, with none of the bother of unprotected premarital sex!

So, you're a single thirtysomething with a few issues. You're a workaholic, or you're immature and irresponsible, or something like that. And on top of that, someone you know (your sister, your best friend, maybe an estranged ex-wife) has just died. Life couldn't possibly get any worse, right?

Wrong. The dead person had a kid, and for some reason, you're the only person who could possibly take them in now. Sucks, doesn't it? You have no experience with kids, and between that and whatever your other problems are, you're really not cut out to be a parent at all. So this is absolutely the last thing you need.

Or at least, that's how you feel at first. But actually, the parenthood that has been suddenly thrust upon you is a good thing. Apparently, having a kid to take care of is like therapy and a dating service rolled into one—by the end of The Movie (or series, or Arc, or what have you), not only will you have learned how to be a good parent (with some hilarious mishaps along the way, most likely) and gotten over all of your issues, you'll have found a love interest too. Now the three of you can be a happy family unit together. Aww.

Frequently used in works starring aging or maturing performers who are seeking to soften their image, to play off of comedic dissonance, or simply because the performer involved wants to do something that is family oriented for a change.

Note: This can, but does not specifically, occur in Soviet Russia.

Promotion to Parent also forces maturity but often with the added toughness of the new "parent" being not much older than the kids.

A common result of Sink-or-Swim Fatherhood. Compare Babies Make Everything Better. See also Resentful Guardian.

Anime and Manga

 * A heartbreaking example in AIR, where the Bottle Fairy mother (actually an aunt)
 * Kanemaki Jisai with Kojiro in Vagabond, partly.
 * This is the central premise of Aishiteruze Baby, where Kippei, a lazy high-school playboy is forced to take care of his five-year-old cousin. The gusto in which he devotes himself to being a good "mother" to Yuzuyu and the speed in which he matures is amazing, as well as quite heartwarming.
 * In the Sahara Mizu manga My Girl, when the protagonist's high school girlfriend dies suddenly, he learns that the real reason she cut off contact with him years ago was to hide the fact that she was pregnant with his child. Said child is now five years old and, of course, has to come live with her father—who is a shy pushover with no idea how to be a parent.
 * In Bunny Drop, 30-year-old bachelor Daikichi Kawachi takes in six-year-old Rin (who happens to be his orphaned aunt, but never mind). From time to time as he learns about the mechanics of parenthood, he wonders just who is raising who.
 * Played with in Witchblade anime: for extra twist, everyone thought that Masane is really Rihoko's mother (even herself, because of Laser-Guided Amnesia). And it's not always clear who's whose custodian. It helps that Rihoko is wise beyond her years and she steals spotlight without even trying, becoming one long Crowning Moment of Awesome diluted with Crowning Moment of Funny.
 * The premise of the anime Daa! Daa! Daa!! is two teenagers who barely know each other, who have to take care of a small baby they find. Of course, the baby is also an alien, but still...
 * In Magical Girl Lyrical Nanoha StrikerS second sound stage, Fate worries that her adoptive children, Erio and Caro, by insisting that they are fine at the moment, are hiding any true problems that they may have (while they don't want to worry her and wish to become a bit more independent). By the end, when they come to an understanding, Fate reflects on Lindy's advice to let your adoptive children raise you, and thinks that was the case when she was being raised by her and Precia (before the latter went insane).
 * In Sakende Yaruze, Shino goes through this process when the 17 year old son he didn't know he had shows up on his doorstep. He moves past his first love (his son's now-deceased mother), gains some emotional maturity, and ends up with a Love Interest as well. However, unlike the happy family unit scenario mentioned above, his new relationship is what causes his son to then leave him and go back to living with his strict grandmother instead.
 * In Detective Conan, The Alcoholic Private Defective Kogoro Mouri was clearly looked after by his 17-year-old daughter Ran.
 * Downplayed in Happy Yarou Wedding. Taking care of the 5 year old Shouta definitely spurs on Yuuhi's emotional growth, but Todou's influence, both as a lover and a quasi-father figure, plays an equal role.
 * In Papa no Iukoto o Kikinasai!, The 19 year-old Yuuta ends up raising his three nieces when his sister and her husband disappear while on a trip. His dedicates his life to taking care of the three girls and matures considerably as a person. This specific trope is dropped at least once a volume in the novels.
 * Rather the point of Otaku no Musume-san. Kouta is a rather immature otaku until his daughter, of whom he had no prior knowledge, drops into his life. Not only taking care of her, but also trying to earn her love and respect forces him to grow the hell up.
 * In Little House With an Orange Roof, Shoutarou is given sole custody of his sons when his wife divorces him. He quickly learns how unprepared he is to be a real parent, though he gets better over time.

Comic Books

 * In Marvel Comics' Crisis Crossover Inferno, a homeless drifter finds a baby that has been orphaned by the demonic invasion. Despite himself, he begins shedding his drunken bum self-image in an effort to protect the child. By the end of the comic, he's all but unofficially adopted the kid.
 * The furry comic Circles has a case of this, where the son was raised until his mid-teens by his mother, then his aunt and uncles when she was killed in a car wreck. The reason the father didn't get custody earlier was because he's gay. Oh, and living with five other gay men, only one of which he's in a relationship with. So far, the kid's doing all right, as are his "new" parents.
 * Northstar, in one issue of Alpha Flight, 'adopted' a foundling.
 * Huey, Louie and Dewey were supposed to stay with their uncle, Donald Duck, only until their dad returned from the hospital (the triplets themselves are responsible for that, by the way). Neither father nor mother are ever referenced again, though, and they have lived with their Unca Donald since then. Good for him, as they save Don from life-threatening situations in a current basis, showing a superior intelligence and maturity level over him. That's not to say Donald hasn't gained any growth from entering paternity; as hilariously dysfunctional as their relationship may be, he effectively serves as the boys' daddy, raising them with his very low income and sincerely wanting the kids to have the best future possible.
 * Rita Moody from Spy Boy.

Films -- Animated

 * Despicable Me, though the girls ended up with him because he adopted them as part of a complicated evil scheme. Before they got attached, he didn't intended to keep them.
 * In The Lego Batman Movie, a good part of Batman character development is triggered when he accidentally adopts Robin and realizes that he has to actually look for him instead of using the kid as a bait for villains.

Films -- Live-Action

 * The German film Mostly Martha and its American remake, No Reservations
 * Raising Helen
 * Training Dad
 * Big Daddy with Adam Sandler, although that one had a bit of a twist; Bedtime Stories might be a little closer to the heart of this trope.
 * Uptown Girls
 * Sleepless in Seattle
 * My Best Friends Girl
 * The Family Man, complete with marriage and suburban lifestyle.
 * The Stepmother, sort of.
 * Three Men and a Baby is a variant where no parental death is involved, just a "runaway mother" approach.
 * Similarly its Indian Remake, Heyy Babyy, which also adds the marriage plot of the above's sequel.
 * The Ur Example: Baby Boom. The baby was left behind by a very distant, European relative that the protagonist hardly even remembered.
 * Jack And Sarah, starring Richard E. Grant. Which contains possibly one of the cutest things ever committed to film, in which Grant (stuck with the baby after his wife suffers Death by Childbirth) carries the baby in a jiffy envelope with a sock on her head as a hat...
 * The sock-on-head bit is copied by Clive Owen in Shoot'Em Up. In his case, the newborn belongs to a woman he's never met before, who suffered Death After Childbirth By Shooting, and he's only looking after it because the Big Bad wants to shoot the baby too. It's that sort of movie.
 * The Game Plan.
 * This was essentially the sub-plot of Like Mike.
 * Tsotsi
 * The Jackie Chan film Rob B Hood, in which he and Louis Koo are thieves who come into the possession of the baby of a billionaire tycoon, and they learn valuable life lessons along the way. Awww.
 * Life As We Know It

Literature

 * About a Boy, both the book and the film (though they do lack the "death" aspect of this trope, the rest fits.)
 * In the last Anne of Green Gables book, Rilla Of Ingleside, Rilla is transformed from a flighty teenager into a responsible, hard-working and inspiring woman as a result of raising a motherless child whose father is off fighting World War I.
 * In Discworld, this seems to have happened to Death, who adopted his daughter, Ysabell, after reaping the souls of her deceased parents. This first-hand interaction with a mortal child (and later Ysabell's daughter, Susan) is presumably a part of why he's developed such a fondness (and attempt to imitate) humanity.
 * In The Bible, Jesus teaches old men in a temple when he's a teen.

Live-Action TV

 * Kevin Hill - A short-lived series about a swinging bachelor and top notch lawyer, suddenly forced to care for his dead cousin's ten month old daughter, Sarah. The show's core centered around Kevin dealing with being a new parent and lawyer at a new smaller firm. The series had a definite Downer Ending when the show canceled in just one season with Kevin losing the baby to her remarried biological mother in court. The series would have continued after that point but did not gain sufficient ratings to be renewed.
 * Ingrained in the premise of My Two Dads.
 * Happens to Shane in season 4 of The L Word.
 * Also part of the premise of The Bernie Mac Show.
 * Star Trek: Deep Space Nine: "The Begotten", where Odo takes care of an infant changeling..
 * An older form of this with Rory pretty much guiding the kitchen and relationship-clumsy Lorelai Gilmore through life in the first four seasons on Gilmore Girls before Executive Meddling and Flanderization kicked in to turn Rory into every other TV teen.
 * Daniel seems to be going this way in Doctors
 * The premise of Raising Hope. As an added bonus, not only does the main character grow as a result as having to look after the titular Hope, but his parents do too.
 * iCarly has a Played for Laughs version with older brother Spencer taking care of sister Carly as their father is on a very long military deployment and the mother is probably dead.

Webcomics

 * In The Inexplicable Adventures of Bob, this seems to be the case with Bob and Jean regarding Molly, to a certain extent. Jean observes this in this strip.

Western Animation

 * Subverted in Transformers Animated, where the Autobots don't think twice about taking Sari in. This is probably before they realize that eight-year-olds aren't user friendly.
 * In Time Squad, Larry and Tuddrussel have enough problems working with each other and doing their job, due to a complete lack of knowledge about history... Until they meet Otto Osworth, an orphaned 8-year-old history buff, who they illegally take into the squad (not without hesitation at first). Otto gains a better life, while Larry and Tuddrussel now have someone to keep them from killing each other; their Like an Old Married Couple dynamic also quickly makes them become like a mother and father to Otto, respectively.
 * Jackie Chan Adventures lampshaded this when it had Jackie admit this when Jade's parents compliment him on taking care of Jade.

Real Life

 * This happens a lot with rock stars and their children. One notable example would be Marlon Richards, son of Keith.