Be sure to stay clear of the third stall on the third floor bathroom—unless you want to come face-to-face with the ghost of a World War II-era girl named Hanako. Rumor has it that by knocking three times on the third stall from the end, then asking if Hanako is in there three times, a little girl with bobbed hair and a red skirt will appear. While she's usually regarded as being harmless, the more gruesome tales say she pulls her prey into the toilet to drown them—as in 2013's gruesome Toire no Hanako-san (Hanako of the Toilet) above.

For a much more sympathetic version, you might want to check Episode 2 of the horror-comedy series Jigoku Sensei Nube (Hell Teacher Nube).

You've just finished your business only to realize that you're out of toilet paper. Suddenly, a voice through the stall asks you to choose between red or blue. You might think of this as some weird but kind gesture, but unbeknownst to you, you have fallen prey to Akai Kami, Aoi Kami (Red Paper, Blue Paper). Either way, you are already doomed.

If you decided to finish up with the red toilet paper, Akai Kami will either slit your throat or peel all of the skin off your body. Think choosing blue is safer? Think again. Aoi Kami will burst in and strangle you to death, leaving your face a purplish-blue color.

So how do you survive this nightmare? Some versions suggest answering a different color will keep the ghost at bay; others say this will only result in the victim being dragged into the underworld. The safest bet might be to answer yellow, which unfortunately means getting doused in urine. Although unpleasant, at least you can escape with your skin intact!

The Aka Manto (Red Cape) dons a crimson cloak and white mask to cover his irresistibly handsome face while stalking his next victim. Depending on the version of the story, as soon as he finds his female prey, he asks, “Would you like a red cape?” If the victim answers in the affirmative, Aka Manto will rip the skin from off his prey’s back, leaving an eerie resemblance of a crimson cape. To avoid this horrific result, simply replying “No, thank you,” will send Aka Manto on his way to his next victim.

Another version draws on themes similar to the Akai Kami, Aoi Kami legend, where instead of choosing between colored paper, the victim must choose between blue and red cloaks with the same gruesome outcomes.

No need for any cleaning supplies in your bathroom so long as you believe in Akaname, the “filth-licker,” a Japanese monster that feeds on the filth and grime that accumulate in dirty bathrooms. This monster is said to have a human-like body and goblin-like face, with slimy hair, one extended toenail on each foot, and a long, pointed tongue excreting poisonous saliva. So long as you don’t get licked by his poisonous tongue, Akaname is relatively harmless, so either leave the cleaning to him and stay out of his way, or clean your bathroom!

Legend says that Reiko Kashima was attacked by a group of men who beat and abused her in a bathroom, then left her to die. Still conscious, the girl started to crawl around crying out for help, but no matter how loudly she screamed, no one could hear her. Finally giving in to exhaustion, she collapsed on top of some railroad tracks by the Meishin Expressway, where eventually a train came along and cut her waist in half, killing her.

Now she proceeds to haunt bathrooms calling out, “Where are my legs?” If you don’t answer, “On the Meishin Expressway,” depending on the version of the legend, she will either cut you in half or take home a souvenir: your leg. If she asks, “Who told you that?” you had better respond with “Reiko Kashima told me,” or risk the chance of having another leg amputated.

Another version of the story features a similarly bisected woman called Teke-Teke, named after the sound she makes when she moves on her hands. Teke-Teke has no relation to washrooms, however.