A large Bonsai Festival held at Omiya Bonsai village in Omiya. During the estical, masterpieces of Bonsai works are exhibited, and Bonsai plants and pots are also sold there.

From May 3rd(Wed) to  5th(Fri) 2017

9:00 Am - 5:00PM(4:00PM on 5th) 

Location: Omiya, Saitama prefecture

Omiya Bonsai Village by Saitama Tourism and International Relations Bureau
http://www.stib.jp/e/tourism/omiyabonsai.html

Related article on digi-joho TOKYO:
 Attractions in Omiya (and how to get there)