From what we understand an official announcement is just days away but the bout has already been agreed between the parties to take place on August 11th at the Korakuen Hall as part of a "Diamond Glove" show. As with all "Diamond Glove" shows that means it will be televised on one of the Fuji TV sister stations.
The bout, for Tobe, would be his first defence of the title he won earlier this year when he stopped Taiki Eto. For Ishida it would be his first title fight of any variety. The prize for both isn't just the title but is also the fact they will move up the world rankings and take a big step towards a world title fight.
At the moment this is the only bout currently being spoken about for the card though we'd expect at least 1 other notable name on the show.
(Image, courtesy of boxingnews.jp, shows Tobe landing a right hand on Eto in his title winning effort from earlier this year).