Subverting the Competence Zone results in one problem. It can be hard explaining why someone much older or younger would follow the cast around in the first place, especially if the story is trying to be realistic in explaining it and the audience immediately assumes they should spend their free time with people their own age. This leads to the reuse of characters, especially as repurposed (and often self-imagined) guardians for characters who didn't have them in the first place. If it's an adult female she's usually unmarried.
Less likely to be lampshaded in a fantastic setting, or if said folks are inhuman or magical in nature. Most of the time the audience doesn't really want an explanation.
- Azumanga Daioh has two unmarried teachers who are on friendly enough terms that they follow their students on vacation. This is probably an exaggeration of the closer relationship Japanese students have with their teachers. Also justifiable because Yukari and Nyamo do have a lot of free time — Yukari is such a jerkass that nobody except Nyamo will voluntarily associate with her, and both of them are single at an age where they'd be expected to be married.
- Lucky☆Star has two such adults, who are used whenever the girls take a driving trip. Kuroi-sensei even manages to invade Konata's online gaming time during the evenings. Likewise, Konata's cousin Yui is around the girls enough that Kuroi assumes Yui has to be unmarried, since we don't see her husband (on business trips) around at all. Konata wondered if that is why Kuroi-sensei became a Christmas Cake.
- Mai Kujaku/Valentine of Yu-Gi-Oh! (who, as a professional duelist, does have quite a bit of free time on her hands) hung out with True Companions eight to ten years younger than herself and fell in love with one of them. Which was justified by her much younger friends also being champion duelists, who she first met in a tournament they were all competing in. Then she joined a cult. Then she suffered a disastrous marriage to... wait, sorry, that was someone else.
- Brock from Pokémon has fallen into this. He originally joined Ash in order to pursue his dream of becoming a Pokémon Breeder, but since returning to the cast in Johto, did little to further this goal and passed up many chances to head out on his own. He did eventually leave the main cast at the end of the Diamond and Pearl series — to become Pokémon Doctor instead, inspired by an experience he had with taking care of sick baby Pokémon on a ship. He has also served as the "doctor" of the group for the majority of his time traveling with Ash and friends.
- Reborn! (2004): Bronco Dino. He's is supposed to be the boss of his own family, but he helps out Tsuna often. One of his men even called this trope by name one time.
- Will from the movie About a Boy has an incredibly large amount of time on his hands. Justified in that he has this time because he lives off royalty checks for a popular fictional Christmas Song his father wrote. Partially deconstructed because he has so much free time, he has no idea what to do with his life.
- Our Miss Brooks: Sixteen-year-old Walter Denton is almost always driving Miss Brooks to school, and often sees her during the day. This in spite of the fact that he is usually portrayed as relatively popular, and likewise has a steady girlfriend.
- Ned's Declassified School Survival Guide: Since Gordy the janitor always slacks off at work, deciding he'll "let the night guy get it," he has plenty of time to hang out with the ¡Three Amigos! and other students, and help with simple plans. And obsessively chase that Weasel Mascot.
- Buffy the Vampire Slayer had a half-decent excuse for why Giles hung around three of the kids in school—they were a freak (Buffy), a dork (Xander), a nerd (Willow), and he was the librarian; where else where they going to hang out? Plus, he was Buffy's Watcher and therefore obligated to watch her. Then, the school blew up. Having also been fired from the Watcher's Council earlier in season 3, he suddenly found himself with a lot of free time in season 4.
- And by the point of season 5, when he got gainful employment again, it didn't need explaining, as the show kept the True Companions concept mostly alive.
- The Janitor from Scrubs, even though he's mentioned that he has a family (his father appears at one point).
- Correction, a man appears at some point.
- He got a Girlfriend in the later seasons.
- A real one. Supposedly. Maybe.
- Now a wife. Who was attracted to him because she's germaphobic. After his marriage in season 8 he doesn't appear as much.
- There's also Jordan, who spends a lot of time at the hospital. She's a board member and only works a few days out of the year and hires a nanny to watch the kids even while she's at home.