The official Japanese website has announced that the Pokémon World Championships Japan Representative Decision Tournament (ポケモンワールドチャンピオンシップス 日本代表決定大会) will be broadcast live on NicoNico on June 14th, 2015 from 12:50 until 16:30 JST. Winners will represent Japan at the Pokémon World Championships which take place in Boston, Massachusetts on August 21st, 2015 until August 23rd, 2015.

Broadcast Times

Junior Finals: 13:00 until 13:15 JST
Seniors Finals: 15:20 until 15:35 JST
Masters Finals: 15:50 until 16:05 JST
Awards Ceremony: 16:10 until 16:25 JST

Sources: http://www.pokemon.co.jp/info/2015/06/150605_gm01.html and http://live.nicovideo.jp/watch/lv223482680