
Here are some hilariously crazy and brilliant inventions only Japan could have thought up:
Napkin Pants

The umbrella for the avid rain-avoider
Air Conditioned Shoes

Umbrella Tie
For those days where you’re not sure if it’s going to rain or not.
Eyedrop Funnels
Sound Catcher Pillow
Now you can still hear the TV when you lay down.
Square Watermelon
Square Watermelons are both easier to pack and ship. They are gown in a case to get them into the shape.
Mobile toilet paper.
Never ending bubble wrap
The perks of having a baby
Metro chin-stick
Hearing Enhancer
If hearing aids are too discrete for you, try one of these hearing enhancers.
Cupmen. It falls down when your noodles are hot
Chopstick Fan
We know you’re busy and don’t want to wait for your noodles to cool on their own. This is for you.
Shoe Umbrellas
Only in Japan. Keep your shoes from getting splashed.
“Solar energy” lighter
Hug-pillow for the lonely woman
Leg pillow for the lonely man
Butter grater
Splash protector for the hairs
A bra that finds you a husband.

Upon choosing a girl, a male can stop the clock by inserting an engagement ring on the bra.
Subway sleeper hat

Allows you to fall asleep during long rides without falling to the floor and lets fellow passengers know when to wake you up so you never miss your stop.
Chopper hand

One-click ctrl+alt+del tool

Roll-up shoes

A flexible pair of shoes that wraps around your feet without you having to tie anything.
Sources : one, two, three