Kamifūsen

[citation needed] Traditionally, kamifūsen were sold in dagashiya, small shops selling candy, snacks and inexpensive toys to schoolchildren as an alternative to the more expensive rubber balloon.

Another variation, known as the kakufūsen (角風船, literally: "angled balloon") is in the shape of a cube rather than a sphere, and is associated with the marketing campaigns of traditional medicine companies.

Much larger kamifūsen, resembling sky lanterns, are flown each year at the Kamihinokinai Paper Balloon Festival (上桧木内の紙風船上げ) in Semboku, Akita.

According to Ichiro Fukumori of the Jet Propulsion Laboratory, "Despite the open hole visible in the silver patch, the kamifūsen stays inflated when bounced on the palm of one’s hand.

[1] A kakufūsen (角風船) (kaku means "angled") is a paper balloon in the shape of a cube rather than a sphere, often used for commercial marketing purposes.

[7] According to tradition, Hiraka Gennai (1728–1780), a scientist in the Edo era, introduced paper balloons as markers for the copper mines in the mountains of the region, and also as entertainment.