Kappa no kawanagare
It’s a pictogram of the stream of Kappa.
Kappa is one of the popular monsters in Japan. Kappa lives in the water and is good at swimming. “Kappa no kawanagare” means that even a good swimmer can be washed away. In other words, it is a Japanese proverb meaning that even the most accomplished person can fail.
Download png of Kappa River Stream here.