Inside Shoes

Called uwabaki, these are cloth-and-rubber slipper-shoes worn by Japanese students in school. Just as one changes out of one's shoes and into slippers upon entering a Japanese home, students change out of their "outdoor shoes" and into uwabaki upon entering school. Special lockers are provided to hold the students' shoes (these are frequently used as mailboxes for notes).

A student's grade level is often indicated by a colored stripe across the toes. Girls often add designs and colors to their uwabaki with markers in order to add some customization and individuality to their school uniforms. Anime with any significant time spent in school inevitably shows characters wearing "inside shoes", whose somewhat informal appearance (often simplified further to ease animation) can make a strange contrast to the more formal school uniforms.

Examples of Inside Shoes include:

Anime and Manga

Sana and all her classmates are shown wearing uwabaki in Kodomo no Omocha.
Neon Genesis Evangelion shows Shinji and Asuka changing into and out of inside shoes more than once, including a scene where Asuka finds love notes in her locker.
Yamada and others in Sister Princess are seen wearing them.
Megumi catches a member of her Instant Fanclub smelling her uwabaki in an early episode of Tenshi na Konamaiki.
- We later find out that Keiko once tried to isolate Megumi by arranging to have everyone else's uwabaki stolen,(including her own), thus casting suspicion on Megumi.
Azumanga Daioh used shoe changing as a scene several times.
- One episode also has Osaka wondering how Westerners live without inside shoes. Specifically, what happens when you step in dog crap and don't realize it.
Haré+Guu references this when Haré points the shoe locker out while playing tour guide to Guu. Naturally the cubbyholes are always empty, since very few of the students actually wear shoes at all.
This was actually kept in the Yu-Gi-Oh! dub.
An example from a series that doesn't take place in school: In Junpei's flashback, these are spotted.
In Suzumiya Haruhi, a dramatic scene where Yuki Nagato protects Kyon from being killed by Ryoko has an interesting floor-level shot where Nagato's name can be seen written on the back of her shoe.
- That very episode features two uses of the shoe lockers as mailboxes, too, both times involving Kyon. The first time, Kyon has no idea who the note's from. It's actually Asakura luring him out to kill him. The second time, it's signed by Mikuru, but it's actually her much older counterpart from the future. Kyon might be justified not taking such shoe locker notes at face value in the future ... or past ... or present. Of course, the use of the locker as a mailbox doesn't go unnoticed.
- In the student film, Yuki's character leaves a note in Koizumi's locker.
- The older version of Mikuru uses the locker to leave Kyon notes with cryptic instructions almost every day in The Scheme of Haruhi Suzumiya.
In Serial Experiments Lain, Lain receives the Psyche chip in her shoe locker.
Can be seen in Fruits Basket, in both the manga and the anime.
Sousuke doesn't quite get the message part and has blown up his locker (message included) more than once.
In volume 1 of Ranma ½ Akane is still wearing her indoor shoes when she challenges Kuno, a neat little detail that indicates just how fast she rushed outside to find Ranma after he jumped out the third-story window into the pool. (She did change her shoes in the anime.)
The English dub of Ghost Stories has Satsuki demand to know why Hajime hasn't taken his shoes off after he's just rescued her by barging into her house. He replies that there's no time for Cultural Translation right now.
The heroine of Saitama Chainsaw Shoujo is lectured by a hall monitor for not changing into her inside shoes when entering the building. Said hall monitor doesn't bother to lecture her on having, by this point, murdered several students with a chainsaw, because that's not in the school regulations.
The inside shoes are also frequently seen in School Rumble - perhaps even more so than "outside" shoes.
In one episode of Hell Girl: The Two Prisoners, the victim of the week is a schoolgirl who is the consistent target of school pranks, which include having thumbtacks put in her inside shoes - which are also scribbled all over with offensive things like "idiot" and "die". Thing is, she does not know who does it until past halfway into the episode.
K-On! has a few not very memorable scenes by the shoe lockers, but paying attention to the color stripes of indoor shoes will alert an astute viewer that Ui performed a Twin Switch on the club when her sister was sick. Her shoes' stripe is red, not blue. And like the Haruhi example above, there are a couple of different shots where Yui's name is visible on her shoes.
In Digimon Adventure 02, it's worth noting that when Hikari and Takeru go to the Digital World from the school computer, their footwear changes from this to sneakers.
In Hidamari Sketch, after a string of bad things happen to Natsume on her first day, the last thing involves her going to the right number, but the wrong department's, shoe lockers, and finding a pair of shoes already there. She is stymied for a few seconds until Sae points out the right set of lockers, and they hurry to the opening ceremony together. This sets up expectations in Natsume's mind that they might become friends, or even best friends... that are at least delayed as Natsume adopts a standoffish attitude toward her as a result of seeing her with Hiro.
- Also, when Yuno and Miyako are hurrying down the hall, one of Yuno's uwabaki comes off and slides ahead of Miyako... who picks it up and runs off playfully, prompting Yuno to chase after.
In Ichigo Mashimaro, when Nobue, Matsuri, and Ana sneak into school after hours to get the recorder that Matsuri forgot, they head for the slippers once inside. Miu, who's going in as well to scare them, predicts this and does not follow this convention, opting instead to set up a scare or two...
In GA Geijutsuka Art Design Class, Kisaragi forgets to change back into her normal shoes, and no one mentions it until they get to the bus stop... at which point, she has to go back.
Numerous episodes of Detective Conan show them used both as shoe lockers and as mail drops - often for some school kid asking for the help of the shounen tanteidan.

Film

In The Fast and the Furious Tokyo Drift, Sean engages in a memorable faux-pas when, out of sheer ignorance, he neglects to put on his uwabaki on his first day at school.

Video Games

A shoe locker appears as the "cubby hole" item in Animal Crossing, complete with a love letter in one of the slots.

Web Comics

Red String portrays the use of these by the high school age cast. Another example of the author actually doing her research.

Real Life

Most Western examples are plimsols or slippers.
- There's also thick socks designed for indoor wear that act like slippers. Probably the best example of Inside Shoes are "dorm slippers", or spandex-and-rubber shoes that are designed to be lightweight and breathe easily.
Canadian elementary schools require a pair of indoor shoes be worn in the building. Seeing as it's Canada, this is to prevent people falling and hurting themselves in hallways coated with snow and slush. Many high schools invoke the practice during the winter months, to prevent the same problem.
Reality Is Unrealistic : Japanese schools may be shifting away from purpose-made uwabaki to letting or having students buy normal sneakers and wear them only inside -- and uniform outdoor shoes are, for some schools, merely a suggestion. It's not uncommon to see students out and about in uniform wearing Crocs or similar.