During yesterday, Square Enix published on their japanese YouTube channel the already announced recap videos for the entire Kingdom Hearts saga. The 5 released videos feature a narration by Chirity, which briefly explains the different chapters of the saga, using both Japanese dub and subtitles. No information about any English translations are known at the moment. These videos are each approximately 3 minutes long. However, when speaking to GNN at E3, Nomura had said these recap videos "might last several hours". You can check below for the full list of videos and the related descriptions below.
UPDATE: Scottyyy has uploaded all the videos with English subtitles! Check it out at the end of this article.
This video shows the departure of Sora for his journey, and recaps Kingdom Hearts story
This video shows the journey of Sora into Castle Oblivion, and recaps Kingdom Hearts Chain of Memories story
This video shows the days of Roxas inside the Organization XIII, and recaps Kingdom Hearts 358/2 Days
This video shows Riku's side of the story, going through the Reverse side of Kingdom Hearts Chain of Memories
This video goes through Master Xehanorth's plan for the 13 Seeker of Darkness as well as part of Birth by Sleep and Dream Drop Distance
A special promotional campaign will be also take place in Shinjuku. The campaign will continue from June 25th to 1st of July, on the expo area of Marunouchi Subway. You can check here for more details.
Kingdom Hearts III releases on PlayStation 4 and Xbox One on January 25, 2019 in Japan, and January 29, 2019 to the rest of the world. You can now watch the latest Frozen trailer, Square Enix E3 Showcase trailer, and Pirates of the Caribbean trailer!
UPDATE: Check out the recap video compilation thanks to Scottyyy! Please enable CC (Closed Caption) to view English subtitles.