Japan has a long history of using cute mascot characters in situations that can surprise Westerners. In fact, quite often the more terrifying or distressing a situation, the cuter the visual description of it becomes on official posters here.
This may sound counterintuitive or even a little condescending at first, but when you start thinking about it, it makes perfect sense. Whereas, say, photos of damage or devastation would probably cause people to avert their eyes, this sort of presentation lures people into actually reading the sign -- particularly children, as tsunami education needs to start early.
Of course, there's no way to know how many lives public-service campaigns like this saved in the 3-11 earthquake and tsunami. But similar to the ancient stone tsunami-warning markers found dotting the countryside, these cute characters are another example that natural disasters are never far from the minds of people in Japan.
A 2007 poster for tsunami evacuation drills in the Sagami Bay area of Kanagawa prefecture (southwest of Tokyo).
A sign spotted in a Shizuoka suburb, explaining how trees can act as wind and wave breaks.
We found this one on a hiking trail in Iwate prefecture several years back. He marks the portions of the trail that pass by the ocean, reminding hikers to beware of tsunami in the event of an earthquake.
Tsunami-man is one of a series of regional mascots from Shikoku's Kochi prefecture used to teach children about the dangers of earthquakes and tsunami. You can see him in action in a comic strip here.
These are just the tip of the iceberg and I am sure there are many more out there. If you know of any, feel free to link to them in the comments.