To promote the upcoming Pocket Monsters Best Wishes movies: Victini and the Light Hero - Reshiram / Victini and the Dark Hero - Zekrom (ビクティニと白き英雄レシラム / ビクティニと黒き英雄ゼクロム), McDonald's Japan has announced a new Happy Set promotion. Starting Friday, June 17th, 2011, participating McDonald's location in Japan will be distributing the 'Playing in the Water Pokémon! (ポケモンと水遊び！)' toys with Happy Set's. Each of these toys are waterproof and can be played with in the water. McDonald's America will also be doing a Happy Meal promotion starting on June 17th, 2011 but the toy distribution is different. Pictures of all the toys can be found on the Imageboard thread.

There are 8 different toys to collect:

Pikachu with Shiny Surfboard (ピカチュウの光るサーフボード)
Zekrom Vehicle (ゼクロム ビークル)
Reshiram Vehicle (レシラム ビークル)
Play in the Water Mijumaru (ミジュマルの水あそび)
Bubbles and Water Gun Pikachu (ピカチュウのシャボン玉と水でっぽう)
Victini Beach
Leaf Boat Tsutarja (ツタージャの木の葉ボート)
Fruit Boat Pokabu (ポカブのフルーツボート).

Source: http://www.terrafor.net/news_e5yWsj4TQ2.html