Handmade by the last craftsman who still today manufactures the traditional Nagasaki kites, whose first specimens with the typical diamond shape date back to the 17th century, these kites have achieved such popularity over the centuries that they had to be regulated, due to the damages they constantly caused to the roofs of the samurai mansions. Also called "groupers" (hata, ハタ), due to their resemblance to the flags (hata, 旗) that flew on the ships of foreign traders, the so-called Nanban, some of the designs still reproduce flags and insignia of Dutch ships, in a perfect combination between East and West.
The blue cross motif takes up precisely a typical nautical signal flag, which attracts the attention of nearby vessels and is therefore a good omen for mutual understanding.
Because it's handmade, each kite is slightly different.
In addition to flying, also in Japan they are often hung on the walls at home, like works of art.