This follows the teaser trailer released for the game on November 24, 2014.
The official story overview from product descriptions translated by Gematsu:
“Arcadia,” a land dominated by swords and magic. A huge tree from ancient times called “Yggdrasil” exists here and is to be the reason that peace visits the world.
There is a legend about that World Tree. If you can manage to reach its untrodden summit, it is said that your dreams will come true.
“The power to dominate the world.” “The most powerful.” “The world’s mysteries.” “Expensive treasures.”
Although there are four races that live in this land, each has a different legend, but no person has been able to confirm them.
From the city “Aolith” at the bottom of Yggdrasil, the official orders are issued. In pursuit of the legend, the courageous adventurers who challenge Yggdrasil will gather in Aolith. And in accordance with official orders, you’ll be the one to gather those adventurers.
Whether it’s for wealth and honor, or to satisfy your sense of adventure, you’ll challenge the labyrinths and aim for the top of the World Tree.
As announced previously, there will be a special Niconico live broadcast for Etrian Odyssey V on March 5, 2016 at 9:00 PM JST (4:00 AM PST / 7:00 AM EST) which will show of the first gameplay trailer for the game to the public, celebrate the series music, and answer questions received via Twitter.
Etrian Odyssey V: The End of the Long Myth will be released for the Nintendo 3DS on August 4, 2016 in Japan.