I read somewhere that it is Kite Day on the 12th May, but on further reading there seems to be a lot of different Kite Days. Flying kites can be such fun for young children and making them even more fun so you probably don't need an excuse to share books about kites at all. In Sydney we have the Festival of Winds in September and I have written about it before here. I wrote here too about my all time favourite kite book, Marcia Vaughan and Patricia Mullins' The Sea Breeze Hotel, but your library might have it. While you are searching look for Marty and Mei-Ling by Phil Cummings and Craig Smith. It too is out of print but also has kite flying as a wonderful community-building catalyst. Two newer books which might inspire you to make and fly kites are:
• Kite Flying by Grace Lim and
• Kite Day by Will Hillenbrand
And while trawling through Google images I found this art work, great to initiate a discussion of the whole role of kites in Japanese culture and to pull out beautiful picture books about Japan.