The official Pokémon movie website has updated. Translations follow:

In Commemoration of "Pocket Monsters the Movie: I Choose You"s Premiere: Pokémon Adventure in Sagamiko Town: Aim to Become A Hero of the Rainbow!

Go on an adventure as a Pokémon Trainer in Sagamiko Town,
following the instructions in the Adventure Book,
befriending the Pokémon in the resort as you search for the legendary Pokémon "Houou" located at the goal!
In the resort you'll find the Pokémon that will cheer you all on,
as well as "Marshadow", who keeps an eye on whether or not you are people qualified to meet Houou (Heroes of the Rainbow),
and they invite you all on a grand adventure.
There's also a photo spot area where you can take a commemorative photo with the Pokémon,
so you'll get to have an experience as if you've almost entered the world of the Pokémon movie itself!
Those who gather their Pokémon companions and successfully meets Houou,
thus clearing the game, will receive a "Houou" sticker!!
Have your entire family go on an adventure together with Pokémon this summer vacation,
at Sagamiko Resort Pleasure Forest!

In Commemoration of "Pocket Monsters the Movie: I Choose You"s Premiere:
Pokémon Adventure in Sagamiko Town: Aim to Become A Hero of the Rainbow!

Event duration: July 14th to August 31st 2017 (current schedule) *limited numbers
Location: Sagamiko Resort Pleasure Forest
Directions:
Get off at Sagamiko Station on the JR Chuo Main Line, then take bus towards Mikage and get off at Pleasure Forest after about 8 minutes.
From Hashimoto Station on the JR Yokohama Line, take bus towards Sagamiko Station (transfer at Mikage Bus Terminal) and get off at Pleasure Forest after about 50 minutes.
Contact: 03-3376-1115 or 042-685-1027

©Nintendo/Creatures/GAME FREAK/TV Tokyo/ShoPro/JR Kikaku ©Pokémon
©2017 Pikachu Project

Source: http://www.pokemon-movie.jp/news/?p=2902