Ema, a wooden plate for dedicating to shrines
Many piles of small wooden plate are called, Ema(絵馬). A horses is drawn on each plate and the plates are dedicated to shrines. Dedicating it to shrine means giving a horse to the gods in shrine to call on them to make one's wishes come true.
The shrine is Yushima Tenjin(湯島天神) and is, first of all, famous for the god of learning. So this shrine is very popular with students taking the entrance exams to universities or high schools.
Most of entrance exams to universities and high school are held from Jan. to Mar. and these plates are dedicated just for telling the god that they passed the exams.
These plates are sold at shrines. Shrines seem to have a talent for business.