Tanzaku (短冊)
Tanzaku means paper cut into strips, or thin slices of wood.
Mostly it is used to write words on, or attached to various things as a sign or marking. Although its main purpose today is to write wishes on as a part of the Tanabata festival (the star festival celebrated on the seventh of July), actually thick and decorated pieces of paper, on which tanka and haiku poems are written, are also a kind of tanzaku.