Japan has one of the world's most extensive urban rail networks, composed of surface trains and subways that carry some 40 million passengers daily in Tokyo. Trains are undoubtedly the most convenient form of transportation in this concrete labyrinth.

Caridges are crowded in the morning and evening commuter rush, packed shoulder-to-shoulder with passengers and even more unpleasant are the bizarre creatures that lurk on these trains.

Let me explain these 10 Yōkai of the Rail System (yōkai are a class of supernatural monsters in Japanese folklore).

1. The Defender

This Yōkai appears in front of the platform-side doors when passengers attempt to exit the train. Regardless of the crowd of people standing at his back, the Defender will firmly hold his position even after the doors have opened and people struggle to squeeze past him before the train departs again. No matter how hard you push and shove, the immovable Defender brandishes his back and maintains a perfect defense.

2. The Backpack

This Yōkai appears on a crowded train hauling a large backpack and stands obliviously in the center of the train, preventing people from passing.

3. The Push

The Push is an impatient Yōkai that appears in the center of the train when the doors open to let people on and off. Seemingly unaware that people are indeed moving toward the doors, the Push repeatedly shoves the people in front of him to urge them forward.

4. The Gap-Tease

The Gap-Tease is a sneaky Yōkai that carefully chooses to sit in a way that leaves a gap on one of both sides of him just small enough to prevent other passengers from sitting down. The result is that only 5 or 6 people have a place to sit on a bench that should hold 7.

5. The Bar Fly

This stubborn Yōkai clings on desperately to the metal bar next to the door no matter the circumstance, and will guard that bar with his life for the feeling of safety it provides him.

6. The Bouncer

You're rushing to get on a commuter train before the doors close. The car in front of you looks at about 90% capacity and, spotting an opening, you rush forward to squeeze yourself in. Suddenly, someone from inside the car steps forward to block your entrance or sticks their leg out from the side as if to say "We're full! You can't come in!"

You've just been blocked by the Bouncer, a Yōkai that is a nuisance to those trying to board a train but a savior to those already in the car.

7. The Background Music (BGM)

This Yōkai has his mp3 player at full volume so that the sound can be heard by those around him, a headache-inducing noise.

8. The Megaphone

These Yōkai always appears in pairs and speak far too excitedly in a voice that resounds throughout the train.

9. The Floor-Squatter

This Yōkai, for some reason, squats in the middle of a crowded train. It's unclear whether the Floor-Squatter is just tired or feeling sick.

10. The Silent-but-Deadly (SBD)

Need we even explain? The SBD is a Yōkai that appears in the middle of a crowded train, pinches out a softy, and disappears back to the netherworld. While the SBD is careful not to make a sound, his product is truly rank and sets of a wave of paranoia as the passengers begin to glance at each other suspiciously.

Those standing near ground zero have it the worse, as they must bear the brunt of the stench and suspicion, and usually end up having their feet stepped on a little more than usual by passive-aggressive passengers on their way out.