Kamada becomes the third Palace player to have his participation confirmed in North America, after Jean-Philippe Mateta and Maxence Lacroix were named in France's squad yesterday.
He is part of a 26-man group who will head across the Atlantic next month.
Japan are in Group F alongside the Netherlands, Tunisia and Sweden and begin their campaign against the Dutch, in Texas on 14 June.
The Palace man is one of three Premier League-based players to feature alongside Liverpool's Wataru Endo and Leeds' Ao Tanaka.
