carp streamer, 鯉魚旗

A father holds up his baby under carp streamers fluttering in a riverside park in Sagamihara, suburban Tokyo, on April 29, 2016 ahead of May 5 Children's Day in Japan.
Some 1,200 carp streamers were hoisted over the Sagami River to celebrate the annual holiday of Children's Day – part of Japan's “Golden Week” holiday which is traditionally one of the busiest travel times of the year. (Photo by Toru Yamanaka/AFP Photo)
The Day in Photos – April 30, 2016, Part 2/2
http://avax.news/fact/The_Day_in_Photos_April_30_2016_Part_2.html