Whether you're traveling Japan via train, on foot, or by car, chances are you'll see a strange decal on a few cars passing by. For the longest time, we at Japanoblog were curious as to what these decals meant, as there was not any self-explaining context. So we found out!
The decals mean different things, depending on what state the driver is in (and no, we're not talking about "drunk" or "sleepy" - in fact, it's illegal to drive (anything) in Japan with a blood alcohol level above 0%).
To our surprise, just about any retail store, including 100-yen stores, carry some, if not all, of these decals for pretty cheap, so if you want/need/require one, just hop on down to your nearest Diaso, Can Do, Seria, Watts, or other 100-yen store to pick one up. Most stores will sell the magnetic decal, and others can sell the suction-type to put on your window.
In fact, these decals are part of the Road Traffic Law Act of 1955, which "is aimed at preventing dangers in the road , ensuring other traffic safety and smoothness, and preventing obstacles resulting from road traffic".
From most to least common, let's start with the one that most people will see anywhere:
Travel just about anywhere around Japan and you're bound to find this decal on some cars, and maybe a moped, motorcycle, or even a horse. Regardless, this means I'm a new driver. These people usually have just come out of Driving School and are instilling the "rules of the road" while gaining practical experience, which includes things such as: no left on red, stopping at railroad crossings, learning how to pass, and other items that are part of everyday driving in Japan.
What is it?
This green and yellow chevron, called a Shoshinsha Mark (初心者マーク) or more commonly called a Wakaba Mark (若葉マーク), is a message to other drivers saying, "I'm still new to driving. If I mess up, I'm sorry." This is similar to the "L-plate" from other countries, such as Australia, Canada, France, the UK, India, and New Jersey). Although people in Japan are usually very friendly, there are those few with some degree of road rage, and will attempt to pass in a no-passing zone or tail if they are in a hurry. There's not much that can be done about these people, but if a Wakaba decal is displayed, they may have some patience with you.
Info about it
In fact, new drivers since 1972 must display this mark on the front and back of their car for at least one year after they pass and obtain a standard driving license. Motorcycles and other vehicles aren't required to have it, but some people feel it necessary to have it to alert others that they are still new to driving. Other countries have adopted this symbol indicating that the person is new in standing.
If you are from another country and you are driving a car (let's assume that you already have your International Drivers Permit), this decal is not required, but it couldn't hurt, especially if you came from a country where the rules are much different (such as driving on the right side of the road, vertical traffic lights, etc).
Fun Fact: Since the symbol has been so widely used by others, the symbol has been represented in Unicode as U+1F530 (?) as part of the Miscellaneous Symbols and Pictographs block.
This one is not as common as the Chevron above, but it does serve a purpose: it alerts others that an elderly person (70 years old and over) is behind the wheel.
However, there may be some confusion to this mark. From 1997 to January 2011, the tear mark was used to indicate this, but from February 2011, the symbol changed to a four-color clover.
What is it?
The old symbol, which some cars still have, is an orange-and-yellow teardrop called a Fukushi Mark or a momiji mark (紅葉マーク, autumn leaf mark), whereas the most recent version is a red/green/light green/yellow clover symbol called a Koreisha Mark (高齢者マーク).
Info about it
If you're under 70 years old, then you don't need to worry about this. However, if you are 70-74, it's highly encouraged to display it. Although people around 70 are more than capable of doing plenty of things in Japan (see how happy they are), there is still the chance that elderly drivers may have some issues, and it would be best for any surrounding people to be informed about it.
If you are 75+, it is required for you to display it on the front and back of your car.
However, outside of Japan, many classic car owners choose to put the tear-drop symbol on their cars, regardless of their age, and others choose to display it to show that they are experienced, versus the Wakaba mark above.
Shintai Shougai Mark
Handicapped: Inverse Clover
While the Chevron and Tear/Clover may be more common, this one and the next one are not as common, but still exist in Japan. This one, the white clover on a blue background, indicates that the driver is handicapped in some way. This does seem like a more friendly way to inform others of a handicapped driver, other than the standard "wheelchair symbol."
What is it?
This symbol is a blue circle with a white clover on it, called a Shintai Shougai Mark. The physical handicap can be anything ranging from wheelchair requirement to crutches and more.
Info about it
It is called the 身体障害 (shintai shougai - physical impairment). Other cars may still display the "wheelchair symbol" to indicate an handicap, so both are still used.
Choukaku Shougai Mark
Hearing Impaired: Butterfly
If you see a yellow butterfly on a car, you might think that it's a cute symbol that someone chose to put there. However, it does mean something: the driver is hearing impaired, which mean that they might or might not hear sirens, horns, train crossings, or other noise deterrents from emergency or passing vehicles.
What is it?
This symbol appears as a yellow butterfly on a green background.
Info about it
It's also called a Choukaku Shougai Mark (聴覚障害).
There you have it! If you see one of these symbols on a car on the road, now you know what they mean. If you need one, you should be able to pick one if not all of them up from your nearest 100-yen store.
/ Clover 
/ Clover 
