The official Pokémon movie website has updated. Translations follow:

The Everyone's "Pokémon Story" Commission

Post your thoughts after watching "Pocket Monsters the Movie: Everyone's Story"
and your memories of Pokémon
to Twitter/Instagram
with the hashtags #ポケモン and #みんなの物語

Rules:
1) Follow the official "Pocket Monsters the Movie: Everyone's Story" Twitter account (@pokemon_movie)
2) Post your thoughts after watching the movie and your memories of Pokémon, using the hashtags #ポケモン and #みんなの物語.
*Please watch out for spoilers.
3) Please note that the comments and photos you post may be published on the official movie site.

How to participate:
To participate, you'll need a Twitter or Instagram account.
Posts without the specified hashtags (#ポケモン #みんなの物語) will be ignored.
If you use Twitter to post, please follow the official "Pocket Monsters the Movie: Everyone's Story" Twitter account (@pokemon_movie). Also, make sure to set your tweets to "Public" before posting.
If you use Instagram to post, please make sure to set your account to "Public" before you post.

It may take time before your post is included in the campaign.
The photos/video/etc you post may be used on this website, other types of movie promotions, etc. Compensation and exploitation rights do not apply in these instances.
Please note that if the organizers decide a picture/video is inappropriate, it will not be published here, or if it is already published, it may be removed without further notice. We do also not have any obligations to explain our reasons or answer inquires regarding the refusal to use a photo/video if this happens.
Submitted photos, video and text will be quoted from Twitter and Instagram. We are thus able to freely edit photos and video before publishing them.
Photos and video must be owned by the poster themselves.
The organizers will bear no responsibility in case of receiving inquires, complaints, injunctions or compensation claims from third parties regarding posted photos or video, and the poster themselves will have to handle and settle all related expenses and responsibilities.
The organizers will bear no responsibility for any damage suffered by the participants due to the creation, posting or use by the organizer of photos or video for any reason (except in case of willful misconduct or gross negligence on the part of the organizers).
Depending on equipment or circumstances, the site may not function.

Disclaimer:
This campaign utilizes services provided by other companies. For this reason, failures and errors not attributable to this company may occur.
We do not accept inquiries regarding selection methods, confirmation on whether a submitted entry has been accepted, or questions regarding anyone's winner status.
This campaign is not connected to Twitter Inc. or Facebook, Inc.
This campaign is subject to change without notice.
We are not responsible for any damages caused by the campaign's interruption or cancellation.

Source: http://www.pokemon-movie.jp/kansou/