Digimon Adventure tri. Chapter 1: Reunion is an anime film that premiered in fall 2015, produced by Toei Animation.

About the production: the story comes from an original script, the film runs about 96 minutes and its current status is "finished".

Its main genres are action, adventure, drama, fantasy and sci-fi, with themes such as Kaiju, Animals, Artificial Intelligence and Ensemble Cast.

On AniList, Digimon Adventure tri. Chapter 1: Reunion has an average score of 71%, a good score, and appears on 26,152 users' lists.

The franchise continues in or follows from: Digimon Adventure 02: Diablomon no Gyakushuu and Digimon Adventure tri. 2: Ketsui.

It's been six years since that summer adventure when Taichi Yagami and the rest of the DigiDestined crossed over to the Digital World. And nearly three years have passed since the final battle between Hikari Yagami's group and BelialVamdemon. As the peaceful days passed by, at some point the gate to the Digital World closed. Not even the DigiDestined know what caused this, and time alone continues to pass. On one such day, a Kuwagamon suddenly appears in Odaiba. Its rampage leaves the town in ruins, and the people there in turmoil. Taichi happens to catch sight of the Kuwagamon, and he chases after it all by himself in an effort to halt its rampage. But there's nothing he can do against a Kuwagamon. "It's no use... I can't do anything about this alone..." Just as the Kuwagamon roars and attacks Taichi, his Digivice begins to emit a bright light... "Taichi, look how big you've grown!" With the sound of that nostalgic voice, the story once again begins to move in a big way. (Source: Official Website)

Official synopsis from AniList.